/*
*obj :事件源对象
*eventStr:事件字符串
*callback:事件触发时执行的函数
*/
function bind(obj,eventStr,callback){
if(obj.addEventListener){
obj.addEventListener(eventStr, callback, false);//大多数主流浏览器支持
}else{
obj.attachEvent("on"+eventStr, function(){//IE8及以下支持
callback.call(obj);
});
}
}
//eg:
var btn = document.getElementById("btn");
bind(btn ,"click" ,function(){
alert("讨厌");
});