为什么window的父窗口为空？
我写了如下的javascript
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN " "http://www.w3.org/TR/html4/loose.dtd ">
<html>
<head>
<meta http-equiv= "Content-Type " content= "text/html; charset=UTF-8 ">
<title> Insert title here </title>
</head>
<body>
<a href= "http://www.163.com " target= "_parent "> www.163.com </a>
<button onclick= "display() "> display parent </button>
<script type= "text/javascript "> <!--
function display(){
var parent = this.parent;
var i = 1;
while(parent != null){
alert(i);
alert(parent);
i++;
if( i == 10){
break;
}
parent = parent.parent;
}
}
--> </script>
</body>
</html>
可是，为什么window.parent却永远不为null呢？奇怪！
[解决办法]
顶层窗口引用的是本身