<script type="text/javascript">   
document.getElementsByClassName = function(className) {   
var children = document.getElementsByTagName('*') || document.all;   
var elements = new Array();   

for (var i = 0; i < children.length; i++) {   
var child = children[i];   
var classNames = child.className.split(' ');   
for (var j = 0; j < classNames.length; j++) {   
if (classNames[j] == className) {   
elements.push(child);   
break;   
}   
}   
}   
return elements;   
}