父节点（parentNode）
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script>
var x = document.getElementsByTagName('a');
window.onload=function(){
for(var i=0;i<x.length;i++){
x[i].onclick=function(){
this.parentNode.style.display='none';
};
}
};
</script>
<title>无标题文档</title>
</head>
<style>
#ul1 li {
list-style: none;
/* background: #C5171A;
*/
/* background: #000000;*/
}
</style>
<div id="ul1">
<li>111<a href="javascript:;"> 隐藏</a></li>
<li>222<a href="javascript:;"> 隐藏</a></li>
<li>333<a href="javascript:;"> 隐藏</a></li>
<li>444<a href="javascript:;"> 隐藏</a></li>
<li>555<a href="javascript:;"> 隐藏</a></li>
</div>
<body>
</body>
</html>
