attachEvent的使用方法与传递参数[IE|firefox]

<input id="button1" type="button" value="按我" /> 
<script language="javascript"> 
window.onload=function(){ 
    var obj=document.getElementById("button1"); 
    (function(){ 
        var str="看到我了吧"; 
        var func=function(){ 
            alert(str); 
        } 
        if (document.all) 
            obj.attachEvent("onclick",func); 
        else 
            obj.addEventListener("click",func,false); 
    })(); 
    alert(typeof(str)); 
} 
</script>