<!DOCTYPE html>
<html>
<body>
<p class="test1"></p>
<p class="test2"></p>
</body>
<script>
function getClass(abc)
{
var reg=new RegExp(abc);
var all=document.all?document.all:document.getElementsByTagName('*');
var l=all.length;
var element=new Array();
for(var i=0;i<l;i++)
{
if(reg.test(all[i].className)){
element[element.length]=all[i];
}
}
document.write(element);
}
getClass("test");
</script>
</html>