Hour : Minute
by Prasanth AR
HTML
<input id="time" type="text"maxlength =5 />
JavaScript
var time = document.getElementById('time');
time.addEventListener('keyup', function(){
var reg = /[0-9]/;
if( this.value.length == 2 && reg.test(this.value) ) this.value = this.value + ":";
});