window.onload 添加多个函数绑定

       window.onload = function(){alert(2)}

	function addEvent (fun) {
		var old = window.onload;
		
		if(typeof old != "function"){
			window.onload = fun;
		}else{
			window.onload = function(){
				old();
				fun();
			}
		}
	}

	function delegationforli(){
		var oul = document.getElementsByTagName(‘ul‘)[0];
		console.log(oul)
		oul.addEventListener(‘click‘,function(e){
			console.log(e.target);
			if(e.target && e.target.nodeName.toLowerCase() == ‘li‘){
				alert(e.target.innerHTML);
			}
		})
	}
	addEvent(delegationforli);