diff --git a/countdown.js b/countdown.js
index 3001c8d..0f7c267 100644
--- a/countdown.js
+++ b/countdown.js
@@ -1,5 +1,63 @@
-function countdown(seconds){
-  // ...
+// Levels
+// Note: All levels wait a second before starting the countdown
+
+// 3. BONUS: don't define any new variables
+
+function countdown(seconds) {
+	setTimeout(timer,1000,seconds);
+}
+
+function timer(seconds) {
+	if ( seconds > 0 ) {
+		document.write("<br/>" + seconds +  "...");
+	} else {
+		document.write("<br/>" + seconds);
+	}
+	seconds--;
+	if ( seconds >= 0 ) {
+		setTimeout(timer,1000,seconds);
+	}
 }
 
+// 2. Keep track of time without defining any global variables
+
+// var intervalID;
+
+// function countdown(seconds) {
+// 	var counter = {
+// 		total : seconds
+// 	};
+// 	intervalID = setInterval(timer,1000,counter);
+// }
+
+// function timer(counter) {
+// 	if ( counter.total === 0 ) {
+// 		document.write("<br/>" + counter.total);
+// 		clearInterval(intervalID);
+// 	} else {
+// 		document.write("<br/>" + counter.total + "...");
+// 		counter.total--;
+// 	}
+// }
+
+// 1. Use global variable to keep track of time
+
+// var counter;
+// var intervalID;
+
+// function countdown(seconds) {
+// 	counter = seconds;
+// 	intervalID = setInterval(timer,1000);
+// }
+
+// function timer() {
+// 	if ( counter === 0 ) {
+// 		document.write("<br/>" + counter);
+// 		clearInterval(intervalID);
+// 	} else {
+// 		document.write("<br/>" + counter + "...");
+// 		counter--;
+// 	}
+// }
+
 countdown(5);