diff --git a/userguide/edit.php b/userguide/edit.php
index f92eec5..4219ef7 100644
--- a/userguide/edit.php
+++ b/userguide/edit.php
@@ -26,6 +26,7 @@
 		const base_dir = '$base_dir/';
 	//]]>
 	</script>
+	<script type="text/JavaScript" src="shared/common.js"></script>
 	<script type="text/JavaScript" src="shared/edit_tool.js"></script>
 
 EOD;
diff --git a/userguide/inc/blocks.php b/userguide/inc/blocks.php
index ea318ce..9317162 100644
--- a/userguide/inc/blocks.php
+++ b/userguide/inc/blocks.php
@@ -132,6 +132,8 @@ function load_doc_with_blocks($doc_id, $lang = null) {
 	// Pass the script path to JavaScript
 	append_js_code($head, $js);
 
+	append_js_file($head, $base_url . '/shared/common.js');
+	append_js_file($head, $base_url . '/shared/blocks.js');
 	append_css_file($head, $base_url . '/shared/blocks.css');
 
 	if ($lang) {
diff --git a/userguide/shared/block_edit_tool.js b/userguide/shared/block_edit_tool.js
index aabcc8b..ae7c6a8 100644
--- a/userguide/shared/block_edit_tool.js
+++ b/userguide/shared/block_edit_tool.js
@@ -1,162 +1,58 @@
-const ping_delay = 60; // in seconds
-
-const attr_trans_id = '_translation_id';
-const attr_state = '_edit_state';
+const edit_tool = '/shared/edit_tool.html';
+const edit_tool_ctx = 'EditBlock';
 
 var edited_node = null;
-var linked_nodes = new Array();
 var original_text;
 
-function endEditionEvent(clickOK) {
-	if (window.edited_node == null)
-		return;
-
-	var id = window.edited_node.getAttribute(attr_trans_id);
-	var next_node = null;
-
-	var new_text = edit_window.document.getElementById('modified').value;
-
-	if (clickOK && new_text) {
-		var not_mark = edit_window.document.getElementById('not_mark').checked;
-
-		source_strings[id] = new_text;
-
-		var xml_http = new XMLHttpRequest();
-
-		var encoded_text = encodeURI(new_text).replace(/&/g, '%26');
-
-		xml_http.open('POST', base_url + '/block_edit.php', true);
-		xml_http.setRequestHeader('Content-Type',
-			'application/x-www-form-urlencoded');
-		xml_http.addEventListener("load", editSaveFinished);
-		xml_http.send('edit_doc=' + doc_id + '&edit_string=' + id +
-			'&edit_text=' + encoded_text + '&dont_mark_fuzzy=' + (not_mark ? '1' : '0'));
-
-		xml_http.userguide_string_id = id;
-		xml_http.userguide_new_text = new_text;
-		return;
-	} else {
-		window.edited_node.innerHTML = formatText(source_strings[id]);
-	}
+function sendEdition(node, id, new_text, not_mark) {
+	var xml_http = HTTPRequest('POST', 'block_edit.php',
+		{
+			edit_doc: doc_id,
+			edit_string: id,
+			edit_text: new_text,
+			dont_mark_fuzzy: (not_mark ? '1' : '0'),
+		} , {
+			load: serverRequestListener,
+		});
+
+	xml_http.userguide_string_id = id;
+	xml_http.userguide_new_text = new_text;
+	xml_http.userguide_fuzzy = !not_mark;
+}
 
-	edit_window.close();
-	edit_window = null;
-	window.edited_node = null;
+function cancelEdition(node, id) {
+	node.innerHTML = formatText(source_strings[id]);
+	node.setAttribute(attr_state, getBlockState(id));
+	closeEditWindow();
 }
 
-function editSaveFinished() {
-	edit_window.focus();
+var removeBlock = cancelEdition;
 
-	var resp = this.responseText,
-		id = this.userguide_string_id,
-		new_text = this.userguide_new_text;
-
-	var send_ok;
-	if (resp.substring(0, 7) == 'badxml ')
-		edit_window.alert('The server rejected the translation because of XML ' +
-			"parsing errors :\n" + this.responseText.substring(3) +
-			"\n" + 'Check the XML tags used in your translation.');
-	else if (resp.substring(0, 6) == 'interr')
-		edit_window.alert('The original XML code seems corrupt. Please contact ' +
-		'an administrator.' + "\n");
-	else if (resp.substring(0, 2) != 'ok')
-		edit_window.alert('There was an error sending the translation. Please ' +
-		'retry.' + "\n" + this.responseText);
-	else
-		send_ok = true;
-
-	for (var i = 0 ; i < linked_nodes[id].length ; i++) {
-		linked_nodes[id][i].innerHTML = formatText(new_text);
-		if (send_ok) {
-			linked_nodes[id][i].removeAttribute(attr_state);
-		} else {
-			linked_nodes[id][i].setAttribute(attr_state, 'error');
-		}
-	}
+function editSaveFinished(id, new_text, fuzzy, send_ok) {
+	edit_window.focus();
 
 	if (!send_ok) {
-		edit_window.focus();
+		window.edited_node.setAttribute(attr_state, 'error');
 		return;
 	}
 
-	edit_window.close();
-	edit_window = null;
-	window.edited_node = null;
-
-	// Refresh the statistics
-	xml_http = new XMLHttpRequest();
-	xml_http.open('GET', base_url + '/update_stats.php?doc_id=' + doc_id, true);
-	xml_http.send(null);
-}
-
-function pingServer() {
-	var xml_http = new XMLHttpRequest();
-
-	xml_http.open('GET', base_url + '/lock.php?doc_id=' + doc_id);
-	xml_http.send(null);
-
-	window.setTimeout(pingServer, ping_delay * 1000);
-}
-
-function mouseClickEvent(e) {
-	if (window.edited_node != null) {
-		edit_window.focus();
-		return false;
-	}
-
-	window.edited_node = this;
+	source_strings[id] = new_text;
+	new_text = formatText(new_text);
+	const state = getBlockState(id);
 
-	var id = this.getAttribute(attr_trans_id);
-
-	edit_window = window.open(base_url + '/shared/edit_tool.html',
-		'Edit Block', 'width=600,height=300,toolbar=0,status=0');
-	window.original_text = source_strings[id];
-
-	return true;
-}
-
-function imgMouseClickEvent(e) {
-	var src = this.getAttribute("src");
-	if (base_local != '.') {
-		src = base_local + '/' + src;
+	for (const node of getBlockNodes(id)) {
+		node.innerHTML = new_text;
+		node.setAttribute(attr_state, state);
 	}
-	window.open(base_url + '/res_upload.php?path=' + encodeURIComponent(src),
-		src, 'width=800,height=600,status=0,toolbar=0,location=0,menubar=0,directories=0,resizable=1,scrollbars=1');
 
-	return true;
-}
+	closeEditWindow();
 
-function setProperties(node) {
-	if (node == null)
-		return;
-
-	if (node.getAttribute) { // Avoid special nodes
-		if (node.getAttribute(attr_trans_id) != null) {
-			var id = node.getAttribute(attr_trans_id);
-
-			if (source_strings[id]) {
-				node.onclick = mouseClickEvent;
-
-				if (linked_nodes[id] == null) {
-					linked_nodes[id] = [ node ];
-				} else {
-					linked_nodes[id].push(node);
-				}
-			}
-
-			return;
-		} else if (node.tagName.toLowerCase() == "img") {
-			node.onclick = imgMouseClickEvent;
-		}
-	}
-
-	for (var i = 0 ; i < node.childNodes.length ; i++) {
-		setProperties(node.childNodes[i]);
-	}
+	// Refresh the statistics
+	HTTPRequest('GET', 'update_stats.php', {doc_id: doc_id});
 }
 
-function formatText(s) {
-	return s.replace(/\{LANG_CODE\}/g, 'en');
+function getBlockState(id) {
+	return '';
 }
 
 window.onload = function() {
@@ -165,17 +61,19 @@ window.onload = function() {
 	if (window.XMLHttpRequest)
 		functions_ok++;
 
-	if (encodeURI)
+	if (Object.entries)
 		functions_ok++;
 
 	if (functions_ok != 2) {
 		window.alert('Your browser does not support some JavaScript ' +
 			'functions which are needed for this page to work correctly. ' +
-			"\nBrowser known to work : Safari 4, Firefox/BeZillaBrowser 2.x, " + "3.x.");
+			"\nTry again with an updated modern browser.");
 		return;
 	} else {
-		window.setTimeout(pingServer, ping_delay * 1000);
+		lockDocument(doc_id);
 	}
 
-	setProperties(document.getElementsByTagName('body')[0]);
+	insertUnreachableBlocks();
+
+	document.addEventListener('click', clickHandler);
 }
diff --git a/userguide/shared/blocks.js b/userguide/shared/blocks.js
new file mode 100644
index 0000000..f8e361f
--- /dev/null
+++ b/userguide/shared/blocks.js
@@ -0,0 +1,128 @@
+const attr_trans_id = '_translation_id';
+const attr_state = '_edit_state';
+
+function clickHandler(e) {
+	var node = e.target;
+	if (node.nodeName.toLowerCase() == 'img') {
+		imgClickHandler(node);
+	} else {
+		node = node.closest('[' + attr_trans_id + ']');
+		if (node != null) {
+			blockClickHandler(node);
+		}
+	}
+}
+
+function imgClickHandler(img) {
+	var src = img.getAttribute("src");
+	if (base_local != '.') {
+		src = base_local + '/' + src;
+	}
+	var lang_param = (typeof lang === 'undefined') ? '' : ('&lang=' + lang);
+	window.open(base_url + '/res_upload.php?path=' + encodeURIComponent(src) + lang_param,
+		src, 'width=800,height=600,status=0,toolbar=0,location=0,menubar=0,personalbar=0,resizable=1,scrollbars=1');
+}
+
+function blockClickHandler(node) {
+	if (window.edited_node != null) {
+		edit_window.focus();
+		return;
+	}
+
+	window.edited_node = node;
+
+	var id = node.getAttribute(attr_trans_id);
+
+	edit_window = window.open(base_url + edit_tool,
+		edit_tool_ctx, 'width=650,height=400,status=0,toolbar=0,location=0,menubar=0,personalbar=0,resizable=1,scrollbars=0');
+	window.original_text = source_strings[id];
+	if (typeof translated_strings !== 'undefined') {
+		window.translated_text = translated_strings[id];
+	}
+}
+
+function endEditionEvent(clickOK) {
+	if (window.edited_node == null)
+		return;
+
+	const node = window.edited_node;
+	const id = node.getAttribute(attr_trans_id);
+
+	if (clickOK) {
+		const new_text = edit_window.document.getElementById('modified').value;
+		if (new_text.trim() == '') {
+			removeBlock(node, id);
+		} else {
+			const fuzzy =
+				edit_window.document.getElementById('fuzzy_check').checked;
+			sendEdition(node, id, new_text, fuzzy);
+		}
+	} else {
+		cancelEdition(node, id);
+	}
+}
+
+function closeEditWindow() {
+	edit_window.close();
+	edit_window = null;
+	window.edited_node = null;
+}
+
+function serverRequestListener() {
+	const resp = this.responseText;
+	var send_ok = false;
+
+	if (resp.substring(0, 7) == 'badxml ')
+		edit_window.alert('The server rejected the change because of XML ' +
+			"parsing errors :\n" + resp.substring(3) +
+			"\n" + 'Check the XML tags.');
+	else if (resp.substring(0, 7) == 'diffxml')
+		edit_window.alert('The server rejected the change because the ' +
+			'XML code used in it differs from the original string.' + "\n" +
+			'Check the XML tags.');
+	else if (resp.substring(0, 6) == 'interr')
+		edit_window.alert('The original XML code seems corrupt. Please contact ' +
+			'an administrator.' + "\n");
+	else if (resp.substring(0, 2) != 'ok')
+		edit_window.alert('There was an error sending the change. Please ' +
+		'retry.' + "\n" + resp);
+	else
+		send_ok = true;
+
+	editSaveFinished(this.userguide_string_id, this.userguide_new_text,
+		this.userguide_fuzzy, send_ok);
+}
+
+function getBlockNodes(id, root = document) {
+	return root.querySelectorAll('[' + attr_trans_id + '="' + id + '"]');
+}
+
+function getAllBlockNodes(root = document) {
+	return root.querySelectorAll('[' + attr_trans_id + ']');
+}
+
+function insertUnreachableBlocks() {
+	// We can't click some translatable blocks (namely title), so we insert
+	// them in the document if there is no other copy.
+	var insertPoint = null;
+
+	const blocks = document.head.querySelectorAll('[' + attr_trans_id + ']');
+	for (const block of blocks) {
+		const id = block.getAttribute(attr_trans_id);
+
+		if (getBlockNodes(id, document.body).length == 0) {
+			if (insertPoint === null) {
+				insertPoint = document.querySelector('h1, h2');
+				if (insertPoint === null) {
+					insertPoint = document.body.firstChild;
+				}
+			}
+
+			var new_node = document.createElement('h1');
+			new_node.innerHTML = block.innerHTML;
+			new_node.setAttribute(attr_trans_id, id);
+			new_node.setAttribute('title', 'This is a fake header for content that the tool cannot reach. It won\'t be here in the final document.');
+			insertPoint.parentNode.insertBefore(new_node, insertPoint);
+		}
+	}
+}
diff --git a/userguide/shared/common.js b/userguide/shared/common.js
new file mode 100644
index 0000000..9c63c77
--- /dev/null
+++ b/userguide/shared/common.js
@@ -0,0 +1,49 @@
+const ping_delay = 60; // in seconds
+
+function HTTPRequest(method, endpoint, params = null, listeners = null) {
+	var xml_http = new XMLHttpRequest();
+	var url = base_url + '/' + endpoint;
+	var body = null;
+	var paramString = null;
+
+	if (params != null) {
+		var paramArray = [];
+		for (const [k,v] of Object.entries(params)) {
+			paramArray.push(encodeURIComponent(k) + '=' + encodeURIComponent(v));
+		}
+		paramString = paramArray.join('&');
+
+		if (method == 'GET') {
+			url = url + '?' + paramString;
+		} else if (method == 'POST') {
+			body = paramString;
+		}
+	}
+
+	if (listeners != null) {
+		for (const [k,v] of Object.entries(listeners)) {
+			xml_http.addEventListener(k, v);
+		}
+	}
+
+	xml_http.open(method, url, true);
+	if (method == 'POST') {
+		xml_http.setRequestHeader('Content-Type',
+			'application/x-www-form-urlencoded');
+	}
+	xml_http.send(body);
+
+	return xml_http;
+}
+
+function lockDocument(doc_id) {
+	function pingServer() {
+		HTTPRequest('GET', 'lock.php', {doc_id: doc_id});
+	}
+
+	setInterval(pingServer, ping_delay * 1000);
+}
+
+function formatText(s, lang = null) {
+	return s.replace(/\{LANG_CODE\}/g, lang || window.lang || 'en');
+}
diff --git a/userguide/shared/edit_tool.html b/userguide/shared/edit_tool.html
index 5e7b8bb..2aa9092 100644
--- a/userguide/shared/edit_tool.html
+++ b/userguide/shared/edit_tool.html
@@ -40,7 +40,7 @@
 <div id="right"><textarea id="modified"></textarea></div>
 <div id="bottom">
 <label style="float:left">
-<input type="checkbox" id="not_mark" /> Do not invalidate translations for this item
+<input type="checkbox" id="fuzzy_check" /> Do not invalidate translations for this item
 </label>
 <input type="button" value="Cancel"
 	onclick="window.opener.endEditionEvent(false);" />
diff --git a/userguide/shared/edit_tool.js b/userguide/shared/edit_tool.js
index 0c72a2e..cb899f3 100644
--- a/userguide/shared/edit_tool.js
+++ b/userguide/shared/edit_tool.js
@@ -1,4 +1,3 @@
-const ping_delay = 60; // in seconds
 const update_delay = 500; // in ms
 
 var preview_window = null;
@@ -9,15 +8,6 @@ var translated_text;
 
 var count = 0;
 
-function pingServer() {
-	var xml_http = new XMLHttpRequest();
-
-	xml_http.open('GET', base_url + '/lock.php?doc_id=' + doc_id);
-	xml_http.send(null);
-
-	window.setTimeout(pingServer, ping_delay * 1000);
-}
-
 function keyDownAction() {
 	var e = event;
 
@@ -44,9 +34,8 @@ function updateStatus() {
 	if (!preview_window)
 		return;
 
-	preview_window.document.write(editor.value
-		.replace('<head>', '<head><base href="' + base_dir + '" />')
-		.replace(/\{LANG_CODE\}/g, 'en'));
+	preview_window.document.write(formatText(editor.value
+		.replace('<head>', '<head><base href="' + base_dir + '" />')));
 	preview_window.document.close();
 }
 
@@ -140,7 +129,7 @@ window.onload = function() {
 		window.alert('Your browser does not support XML HTTP requests. ' +
 			'You will not be protected against concurrent edits!');
 	} else {
-		window.setTimeout(pingServer, ping_delay * 1000);
+		lockDocument(doc_id);
 	}
 
 	preview_button = document.getElementById('preview');
diff --git a/userguide/shared/tool.css b/userguide/shared/tool.css
index ffa9bbf..2fd0082 100644
--- a/userguide/shared/tool.css
+++ b/userguide/shared/tool.css
@@ -73,7 +73,7 @@ textarea, input, button {
 	margin-left: 5px;
 }
 
-#original, #translated, #modified {
+#original, #modified {
 	width: 99%;
 	height: 99%;
 }
diff --git a/userguide/shared/translate_tool.html b/userguide/shared/translate_tool.html
index 46164bd..f33efe3 100644
--- a/userguide/shared/translate_tool.html
+++ b/userguide/shared/translate_tool.html
@@ -36,7 +36,7 @@
 var last_update_text = '';
 
 function updateEvent() {
-	var text = document.getElementById('translated').value
+	var text = document.getElementById('modified').value
 
 	if (text == last_update_text) {
 		window.setTimeout(5000);
@@ -58,7 +58,7 @@
 		window.opener.original_text);
 
 	document.getElementById('original').value = window.opener.original_text;
-	document.getElementById('translated').value = text;
+	document.getElementById('modified').value = text;
 
 	document.getElementById('valid_button').value =
 		'Send ' + window.opener.lang_name + ' Translation';
@@ -69,10 +69,10 @@
 		pos = selectText(text);
 
 	if (pos)
-		document.getElementById('translated').setSelectionRange(pos[0], pos[1]);
+		document.getElementById('modified').setSelectionRange(pos[0], pos[1]);
 	else {
-		document.getElementById('translated').focus();
-		document.getElementById('translated').select();
+		document.getElementById('modified').focus();
+		document.getElementById('modified').select();
 	}
 
 	window.setTimeout(updateEvent, 500);
@@ -106,13 +106,13 @@
 <div id="topright">Translated text</div>
 <form action="#" method="post">
 <div id="left"><textarea id="original" readonly="readonly"></textarea></div>
-<div id="right"><textarea id="translated"></textarea></div>
+<div id="right"><textarea id="modified"></textarea></div>
 <div id="bottom">
 <label style="float:left">
 <input type="checkbox" id="auto_cont" /> Go to next block after validation
 </label>
 <label style="float:left;margin-left:2em;" title="If checked, the translation will be marked as “possibly invalid” and won’t be included into the translation until further review.">
-<input type="checkbox" id="mark_fuzzy" /> Fuzzy
+<input type="checkbox" id="fuzzy_check" /> Fuzzy
 </label>
 <input type="button" value="Cancel"
 	onclick="window.opener.endEditionEvent(false);" />
diff --git a/userguide/shared/translate_tool.js b/userguide/shared/translate_tool.js
index d041e28..3f36b61 100644
--- a/userguide/shared/translate_tool.js
+++ b/userguide/shared/translate_tool.js
@@ -1,100 +1,61 @@
-const attr_trans_id = '_translation_id';
-const attr_state = '_edit_state';
+const edit_tool = '/shared/translate_tool.html';
+const edit_tool_ctx = 'TranslateBlock';
 
 var edit_window = null;
 var edited_node = null;
 var original_text;
 var translated_text;
-var linked_nodes = new Array();
 var all_nodes = new Array();
 
-var title_id = 0;
-var title_insert = false;
-var first_title = null;
-
-function endEditionEvent(clickOK) {
-	if (window.edited_node == null)
-		return;
-
-	var id = window.edited_node.getAttribute(attr_trans_id);
-	var next_node = null;
-
-	if (clickOK) {
-		var trans = edit_window.document.getElementById('translated').value;
-		var mark_fuzzy = edit_window.document.getElementById('mark_fuzzy').checked;
-
-		translated_strings[id] = trans;
+function sendEdition(node, id, trans, mark_fuzzy) {
+	var xml_http = HTTPRequest('POST', 'translate.php',
+		{
+			translate_lang: lang,
+			translate_doc: doc_id,
+			translate_string: id,
+			translate_text: trans,
+			translate_source: source_strings[id],
+			is_fuzzy: (mark_fuzzy ? '1' : '0'),
+		} , {
+			load: serverRequestListener,
+		});
+
+	xml_http.userguide_string_id = id;
+	xml_http.userguide_new_text = trans;
+	xml_http.userguide_fuzzy = mark_fuzzy;
+}
 
-		var xml_http = new XMLHttpRequest();
+function cancelEdition(node, id) {
+	var text = translated_strings[id] == '' ? source_strings[id] : translated_strings[id];
+	node.innerHTML = formatText(text);
+	node.setAttribute(attr_state, getBlockState(id));
+	closeEditWindow();
+}
 
-		var encoded_source = encodeURI(source_strings[id]).replace(/&/g, '%26').replace(/\+/g, '%2B');
-		var encoded_translation = encodeURI(trans).replace(/&/g, '%26').replace(/\+/g, '%2B');
+function removeBlock(node, id) {
+	// TODO: currently gives an error due to empty text, but could be used
+	// to remove a translation
+	sendEdition(node, id, '', false);
+}
 
-		xml_http.open('POST', base_url + '/translate.php', true);
-		xml_http.addEventListener("load", translateSaveFinished);
-		xml_http.setRequestHeader('Content-Type',
-			'application/x-www-form-urlencoded');
-		xml_http.send('translate_lang=' + lang + '&translate_doc=' + doc_id +
-			'&translate_string=' + id + '&translate_text=' + encoded_translation +
-			'&translate_source=' + encoded_source + '&is_fuzzy=' + (mark_fuzzy ? '1' : '0'));
+function editSaveFinished(id, trans, fuzzy, send_ok) {
+	edit_window.focus();
 
-		xml_http.userguide_string_id = id;
-		xml_http.userguide_trans = trans;
-		xml_http.userguide_mark_fuzzy = mark_fuzzy;
+	if (!send_ok) {
+		window.edited_node.setAttribute(attr_state, 'error');
 		return;
-	} else {
-		window.edited_node.innerHTML = formatText(translated_strings[id]);
-		if (window.edited_node.innerHTML == ''
-			|| window.edited_node.innerText == '')
-			window.edited_node.innerHTML = formatText(source_strings[id]);
-		translateBlockDone(next_node);
 	}
-}
 
-function translateSaveFinished() {
-	edit_window.focus();
-
-	var resp = this.responseText;
-	var id = this.userguide_string_id;
 	var next_node;
 
-	var send_ok;
-	if (resp.substring(0, 7) == 'badxml ')
-		edit_window.alert('The server rejected the translation because of XML ' +
-			"parsing errors :\n" + this.responseText.substring(3) +
-			"\n" + 'Check the XML tags used in your translation.');
-	else if (resp.substring(0, 7) == 'diffxml')
-		edit_window.alert('The server rejected the translation because the ' +
-			'XML code used in it differs from the original string.' + "\n" +
-			'Check the XML tags used in your translation.');
-	else if (resp.substring(0, 6) == 'interr')
-		edit_window.alert('The original XML code seems corrupt. Please contact ' +
-			'an administrator.' + "\n");
-	else if (resp.substring(0, 2) != 'ok')
-		edit_window.alert('There was an error sending the translation. Please ' +
-		'retry.' + "\n" + this.responseText);
-	else
-		send_ok = true;
-
-	is_fuzzy[id] = this.userguide_mark_fuzzy;
-
-	for (var i = 0 ; i < linked_nodes[id].length ; i++) {
-		linked_nodes[id][i].innerHTML = formatText(this.userguide_trans);
-
-		if (send_ok) {
-			if (this.userguide_mark_fuzzy) {
-				linked_nodes[id][i].setAttribute(attr_state, 'fuzzy');
-			} else {
-				linked_nodes[id][i].removeAttribute(attr_state);
-			}
-		} else {
-			linked_nodes[id][i].setAttribute(attr_state, 'error');
-		}
-	}
+	is_fuzzy[id] = fuzzy;
+	translated_strings[id] = trans;
+	trans = formatText(trans);
+	const state = getBlockState(id);
 
-	if (!send_ok) {
-		edit_window.focus();
-		return;
+	for (const node of getBlockNodes(id)) {
+		node.innerHTML = trans;
+		node.setAttribute(attr_state, state);
 	}
 
 	if (edit_window.document.getElementById('auto_cont').checked) {
@@ -120,98 +81,29 @@ function translateBlockDone(next_node) {
 		window.translated_text = translated_strings[id];
 		window.setTimeout(edit_window.refreshAll, 0);
 	} else {
-		edit_window.close();
-		edit_window = null;
-		window.edited_node = null;
+		closeEditWindow();
 	}
 }
 
-function mouseClickEvent(e) {
-	if (window.edited_node != null) {
-		edit_window.focus();
-		return false;
+function getBlockState(id) {
+	if (translated_strings[id] == '') {
+		return 'untranslated';
+	} else if (is_fuzzy[id]) {
+		return 'fuzzy';
 	}
-
-	window.edited_node = this;
-
-	var id = this.getAttribute(attr_trans_id);
-
-	edit_window = window.open(base_url + '/shared/translate_tool.html',
-		'Edit Translation', 'width=650,height=400,status=0,toolbar=0,location=0,menubar=0,directories=0,resizable=1,scrollbars=0');
-	window.original_text = source_strings[id];
-	window.translated_text = translated_strings[id];
-
-	return true;
-}
-
-function imgMouseClickEvent(e) {
-	var src = this.getAttribute("src");
-	if (src != '.') {
-		src = base_local + '/' + src;
-	}
-	window.open(base_url + '/res_upload.php?path=' + encodeURIComponent(src) + '&lang=' + lang,
-		src, 'width=800,height=600,status=0,toolbar=0,location=0,menubar=0,directories=0,resizable=1,scrollbars=1');
-
-	return true;
+	return '';
 }
 
-function setProperties(node) {
-	if (node == null)
-		return;
+function initializeNode(node) {
+	const id = node.getAttribute(attr_trans_id);
+	const state = getBlockState(id);
 
-	if (node.getAttribute) { // Avoid special nodes
-		if (node.getAttribute(attr_trans_id) != null) {
-			var id = node.getAttribute(attr_trans_id);
-
-			if (source_strings[id]) {
-				var node_name = node.tagName.toLowerCase();
-
-				if (node_name != "title") { // We can't touch it
-					if (translated_strings[id] == '') {
-						node.setAttribute(attr_state, 'untranslated');
-					} else if (is_fuzzy[id]) {
-						node.setAttribute(attr_state, 'fuzzy');
-						node.innerHTML = formatText(translated_strings[id]);
-					} else {
-						node.innerHTML = formatText(translated_strings[id]);
-					}
-
-					node.onclick = mouseClickEvent;
-
-					node.setAttribute('_internal_id', all_nodes.length);
-					all_nodes.push(node);
-
-					if (linked_nodes[id] == null) {
-						linked_nodes[id] = [ node ];
-					} else {
-						linked_nodes[id].push(node);
-					}
-				}
-
-				if (title_id == 0 && node_name == "title") {
-					title_id = id;
-					title_insert = true;
-				} else if (id == title_id) {
-					title_insert = false;
-				}
-
-				if (first_title == null && (node_name == "h1" || node_name == "h2")) {
-					first_title = node;
-				}
-			}
-			return;
-		} else if (node.tagName.toLowerCase() == "img") {
-			node.onclick = imgMouseClickEvent;
-		}
-	}
-
-	for (var i = 0 ; i < node.childNodes.length ; i++) {
-		setProperties(node.childNodes[i]);
+	if (translated_strings[id] != '') {
+		node.innerHTML = formatText(translated_strings[id]);
 	}
-}
-
-function formatText(s) {
-	return s.replace(/\{LANG_CODE\}/g, lang);
+	node.setAttribute(attr_state, state);
+	node.setAttribute('_internal_id', all_nodes.length);
+	all_nodes.push(node);
 }
 
 window.onload = function() {
@@ -220,32 +112,20 @@ window.onload = function() {
 	if (window.XMLHttpRequest)
 		functions_ok++;
 
-	if (encodeURI)
+	if (Object.entries)
 		functions_ok++;
 
 	if (functions_ok != 2) {
 		window.alert('Your browser does not support some JavaScript ' +
 			'functions which are needed for this page to work correctly. ' +
-			"\nBrowser known to work : Safari 4, Firefox/BeZillaBrowser 2.x, " + "3.x.");
+			"\nTry again with an updated modern browser.");
 		return;
 	}
 
-	setProperties(document.getElementsByTagName('html')[0]);
-
-	if (title_insert) {
-		// The translatable text used in the <title> tag is not used anywhere else.
-		// Since the translate tool does not allow translating <title>, we must insert
-		// this text somewhere.
-		var new_title = document.createElement("h1");
-		new_title.setAttribute(attr_trans_id, title_id);
-		new_title.appendChild(document.createTextNode(source_strings[title_id]));
-
-		if (first_title != null && first_title.parentNode != null) {
-			first_title.parentNode.insertBefore(new_title, first_title);
-		} else {
-			document.body.insertBefore(new_title, document.body.firstChild);
-		}
-
-		setProperties(new_title);
+	insertUnreachableBlocks();
+	for (const node of getAllBlockNodes()) {
+		initializeNode(node);
 	}
+
+	document.addEventListener('click', clickHandler);
 }