IE浏览器不支持getElementsByClassName解决办法

function test(){
var obj=document.getElementsByClassName(”qq”);
for (var i=0;i obj[i].style.color=”#ff0000″;
}
}

function test2(){
var obj=document.getElementsByClassName(”qq”,”DIV”);
for (var i=0;i obj[i].style.color=”#ff0000″;
}
}

function test3(){
var myid=document.getElementById(’ok’);
var obj=document.getElementsByClassName(”qq”,”DIV”,myid);
for (var i=0;i obj[i].style.color=”#ff0000″;
}
}

if (navigator.appName == 'Microsoft Internet Explorer') {
document.getElementsByClassName = function() {
var tTagName = "*";
if (arguments.length > 1) {
tTagName = arguments[1];
}
if (arguments.length > 2) {
var pObj = arguments[2]
} else {
var pObj = document;
}
var objArr = pObj.getElementsByTagName(tTagName);
var tRObj = new Array();
for ( var i = 0; i < objArr.length; i++) {
if (objArr[i].className == arguments[0]) {
tRObj.push(objArr[i]);
}
}
return tRObj;
}
}