Possible Duplicate:
How to create a JQuery Clock / Timer
Does anyone knows countdown timer using javascript??
Using pure javascript, you would use the setTimeout
method in a manner similar to this (treat this code as pseudocode, it is just to show the concept, I do not think it will work as-is):
countdown = function()
{
var current = parseInt(document.getElementById("countdownBox").innerHTML);
document.getElementById("countdownSpan").innerHTML = current;
if (current > 0)
{
setTimeout('countdown()', 1000); // run every second
}
}
You would start the countdown by writing something in the element with id countdownBox
and calling countdown()
for the first time.
Edit: note that the setTimeout
method will tend to lose seconds if used this way - if you want real precision you will most likely have to synchronize externally every once in a while.