封裝兼容性添加、刪除事件的函數 addEventListener與removeEventListener

var Event = {
    addHandler: function (oElement, sEvent, fnHandler) {
        oElement.addEventListener ? oElement.addEventListener(sEvent, fnHandler, false) : oElement.attachEvent("on" + sEvent, fnHandler)    
    },
    removeHandler: function (oElement, sEvent, fnHandler) {
        oElement.removeEventListener ? oElement.removeEventListener(sEvent, fnHandler, false) : oElement.detachEvent("on" + sEvent, fnHandler)
    }
}
window.onload = function ()
{
    var aBtn = document.getElementsByTagName("input");
    
    //為第一個按鈕添加綁定事件
    aBtn[1].onclick = function ()
    {
        Event.addHandler(aBtn[0], "click", fnHandler);    
        aBtn[0].value = "我可以點擊了"
    }
    
    //解除第一個按鈕的綁定事件
    aBtn[2].onclick = function ()
    {
        Event.removeHandler(aBtn[0], "click", fnHandler);
        aBtn[0].value = "毫無用處的按鈕"    
    }
    
    //事件處理函數
    function fnHandler ()
    {
        alert("事件綁定成功！")    
    }
}

<input type="button" value="毫無用處的按鈕"> <input type="button" value="綁定click"> <input type="button" value="解除綁定">