[bodaudinh]

In my code, I FIND by Classname (with the key=rainbow), it'll run ONCE time.

var b = getElementsByClassName(classname);

But in your code, you search by FOR LOOP by TagName with span. How long for ??? Do u thinking abt that ?

var aspans = document.getElementsByTagName('span');
	for (var i = 0; i < aspans.length; i++)
	{

have 4 functions, It does not run slowly... U can check it again . Faster ???