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 oldfn=window.onload
        if(typeof window.onload !='function')    window.onload=fn;
        else    window.onload=function(){oldfn();fn();}
    }
}