A simple countdown timer in Javascript

countdown.js

/********************************************************************************************************************
Countdown.js is a simple script to add a countdown timer
for your website. Currently it can only do full minutes
and partial minutes aren't supported. This script is a fork of http://jsfiddle.net/HRrYG/ with some 
added extensions. Since the original code that I forked was released under Creative Commons by SA license, 
I have to release this code under the same license. You can view a live demo of this code at http://jsfiddle.net/JmrQE/2/.
********************************************************************************************************************/
function countdown(minutes) {
    var seconds = 60;
    var mins = minutes
    function tick() {
        //This script expects an element with an ID = "counter". You can change that to what ever you want. 
        var counter = document.getElementById("counter");
        var current_minutes = mins-1
        seconds--;
        counter.innerHTML = current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
        if( seconds > 0 ) {
            setTimeout(tick, 1000);
        } else {
            if(mins > 1){
                countdown(mins-1);           
            }
        }
    }
    tick();
}
//You can use this script with a call to onclick, onblur or any other attribute you would like to use. 
countdown(n);//where n is the number of minutes required.