function addLoadListener(fn)
{
    if(typeof window.addEventListener !='undefined')
    {
        window.addEventListener('load',fn,false);
    }
    else if(typeof document.addEventListener !='undefined')
    {
        document.addEventListener('load',fn,false);
    }
    else if(typeof window.attachEvent !='undefined')
    {
        window.attachEvent('onload',fn);
    }
    else
    {
        var old=window.onload;
        if(window.onload !='function')
        {
            window.onload=fn;
        }
        else
        {
            window.onload=function()
            {
                old();
                fn();
            }
        }
    }
}
function addEventListener(target,eventType,functionRef,capture)
{
    if(typeof target.addEventListener !="undefined")
    {
        target.addEventListener(eventType,functionRef,capture);
    }
    else if(typeof target.attachEvent !="undefined")
    {
        target.attachEvent("on"+eventType,functionRef);
    }
    else
    {
        eventType="on"+eventType;
        if(typeof target[eventType] =="function")
        {
            var old=target[eventType];
            target[eventType]=function()
            {
                old();
                return functionRef();
            };
        }
        else
        {
            target[eventType]=functionRef;
        }
    }
}
addLoadListener(x);
function x()
{
alert("xx");
}
而删除addEventListener,又能执行得么,,不晓得是什么原因,,与addEventListener有什么关系?
请高手解答

上面的alert执行不到,,要删除addEventListener才能执行得到,不用监听器,直接用window.onload=xx;又得行,是冲突了嘛

如果是冲突,那怎么样调用addEventListener来处理load事件

你自定义的addEventListener，为global作用域下的函数，即任何在global作用域下定义的变量或函数，其实是会自动成为window的成员变量或函数，即比如

var member = function() {}
则不但可以通过member()来访问，同样可以通过window.member()来访问

而你自定义的addEventListener，覆盖了原有的window.addEventListener

解决办法是用一个对象来包含这两个方法

谢谢!就只改哈第二个function函数名就可以了