JavaScriptEvent学习补遗addEventSimple

functionaddEventSimple(obj,evt,fn){
    if(obj.addEventListener)
        obj.addEventListener(evt,fn,false);
    elseif(obj.attachEvent)
        obj.attachEvent("on"+evt,fn);
}

functionremoveEventSimple(obj,evt,fn){
    if(obj.removeEventListener)
        obj.removeEventListener(evt,fn,false);
    elseif(obj.detachEvent)
        obj.detachEvent("on"+evt,fn);
}