是事件冒泡的锅吗?若果是，cancelbubble加到哪一行下面？若果不是应该怎么改.

下拉菜单

body,ul,li{ margin:0; padding:0; font-size:13px;}

ul,li{list-style:none;}

#divselect{width:186px; margin:80px auto; position:relative; z-index:10000;}

#divselect cite{width:150px; height:24px;line-height:24px; display:block; color:#807a62; cursor:pointer;font-style:normal;

padding-left:4px; padding-right:30px; border:1px solid #333333;

/*background:url(xjt.png) no-repeat right center;*/}

#divselect ul{width:184px;border:1px solid #333333; background-color:#ffffff; position:absolute; z-index:20000; margin-top:-1px; display:none;}

#divselect ul li{height:24px; line-height:24px;}

#divselect ul li a{display:block; height:24px; color:#333333; text-decoration:none; padding-left:10px; padding-right:10px;}

window.οnlοad=function(){

var box=document.getElementById('divselect'),

title=box.getElementsByTagName('cite')[0],

menu=box.getElementsByTagName('ul')[0],

as=box.getElementsByTagName('a'),

index=-1;

// 点击三角时

title.οnclick=function(event){

event = event||window.event;

menu.style.display = 'block';

if(event.stopPropagation){

event.stopPropagation();

}else{

event.cancelBubble = true;

}

document.onkeyup = function(event){

event = event||window.event;

if(event.keyCode==40){

index++;

if(index>=as.length) index=0;

for(var i=0; i

as[i].style.background = '#fff';

}

as[index].style.background = '#ccc';

}

if(event.keyCode==38){

index--;

if(index<0) index=as.length-1;

for(var i=0; i

as[i].style.background = '#fff';

}

as[index].style.background = '#ccc';

}

if(event.keyCode==13){

for(var i=0; i

as[i].style.background = '#fff';

}

title.innerHTML = as[index].innerHTML;

menu.style.display = 'none';

}

}

}

// 滑过滑过、离开、点击每个选项时

for(var i=0; i

as[i].num = i

as[i].onmouseover = function(){

this.style.background = '#ccc'

index = as[i].num-1;

}

as[i].onmouseout = function(){

this.style.background = '#fff'

}

as[i].onclick = function(event){

event = event||window.event;

if(event.stopPropagation){

event.stopPropagation();

}else{

event.cancelBubble = true;

}

menu.style.display = 'none';

title.innerHTML = this.innerHTML;

}

}

// 点击页面空白处时

document.onclick = function(){

menu.style.display = 'none';

}

}