js检测网络是否具体连接功能的代码

varEventUtil={
addHandler:function(element,type,handler){
if(element.addEventListener){
element.addEventListener(type,handler,false);
}elseif(element.attachEvent){
element.attachEvent("on"+type,handler);
}else{
element["on"+type]=handler;
}
},
removeHandler:function(element,type,handler){
if(element.removeEventListener){
element.removeEventListener(type,handler,false);
}elseif(element.detachEvent){
element.detachEvent("on"+type,handler);
}else{
element["on"+type]=null;
}
}
};

vardom=document.createElement("img");
dom.style="display:none;";
dom.src="http://www.baidu.com/img/bdlogo.gif";
dom.id="map_img";
EventUtil.addHandler(dom,"error",function(){

alert("你的电脑没有链接网络，连接上网络后才能打开地图！");
});
document.body.appendChild(dom);