CODE EXAMPLE FOR JAVASCRIPT

repeating countdown timer javascript

var count=25;

var counter=setInterval(timer, 1000); //1000 will  run it every 1 second

function timer()
{
  count=count-1;
  if (count <= 0)
  {
    clearInterval(counter);
    return;
   }

 document.getElementById("timer").innerHTML=count; // watch for spelling
 }