如何避免Javascript事件绑定出现内存泄漏

"These memory leaks often
occur as a result of circular references between JavaScript objects and
objects within IE’s DOM (document object model)."
GPDE Team Blog
明显的DOM对象与 JavaScript对象循环引用很好判断，难的是隐含的循环引用判断！
隐含的循环引用需要通过作用域链进行分析判断！
考虑以下代码(感谢可爱的winter ^_^)：
var e=document.getElementBy??("XX");
e.onclick=function(){}
scopechain分析：
scopechain.e = document.getElementBy??("XX");
function f(){}
function f(){}.[[scope]] = scopechain
e.onclick = f
很清晰，对不对？
"Javascript绑定事件时，只要DOM的事件里访问不了DOM自己的那个变量就行了"
winter
"IE现在的Patch搞得有时候泄露有时候不泄露"
winter
<button id="testx">No Memory Leak Event Bind</button>
<button id="testy">No Memory Leak Event Bind</button>
<script type="text/javascript">
var fooA = function(){
    var f = function(){alert(this+'\n'+fooA);}
    !function(){
        var d = document.getElementById('testx');
        d.onclick = f;
    }()
}
fooA();
var fooB = function(){
    this.onclick = function(){alert(this+'\n'+fooB);}
}
fooB.call(document.getElementById('testy'));
</script>