function getElementsByClassName(str,root,tag){
		if(root){
			root=typeof root=="string"?document.getElementById(root):root;
		}else{
			root=document.body;
		}
		tag=tag||"*";
		var els=root.getElementsByTagName(tag),arr=[];
		for(var i=0,n=els.length;i<n;i++){
			for(var j=0,k=els[i].className.split(" "),l=k.length;j<1;j++){
				if(k[j]==str){
					arr.push(els[i]);
					break;
				}
			}
		}
		return arr;
}

function attachEvent(node,eventType,handler){
	node=typeof node=="string"?document.getElementById(node):node;
	if(typeof(handler) != 'undefined'){
		if(document.all){
			node.attachEvent("on"+eventType,handler);
		}else{
			node.addEventListener(eventType,handler,false);
		}
	}
	
}

function getEventTarget(e){
	e=window.event||e;
	return e.srcElement||e.target;
}