IE，FF下getElementsByName无效

var lis = getElementsByName("li",name);//第一个参数为tag标签

var getElementsByName = function(tag, name){
var doms = document.getElementsByName(name);
//获取到
 if(doms.length > 0) return doms;
//获取不到
doms = new Array();
var e = document.getElementsByTagName(tag);//先通过tag获取dom
for(var i = 0; i < e.length; i++){
if(e[i].getAttribute("name") == name){
doms[doms.length] = e[i];
}
}
return doms;
}