JavaScript动态创建iframe，可以指定加载成功和超时回调

function createIframe(id,url,width,height,onLoadCallback,timeOut,timeOutCallback){
    var timeOutVar = setTimeout(function(){
        clearTimeout(timeOutVar);
        timeOutCallback.apply(this, arguments);
        return ;
    }, timeOut);
    var iframe = document.createElement("iframe");
    iframe.id=id;
    iframe.width=width;
    iframe.height=height;
    iframe.src=url;
    if (iframe.attachEvent){
        iframe.attachEvent("onload", function(){
                clearTimeout(timeOutVar);
            onLoadCallback.apply(this, arguments);
        });
    } else {
        iframe.onload = function(){
                clearTimeout(timeOutVar);
            onLoadCallback.apply(this, arguments);
        };
    }
    document.body.appendChild(iframe);
    return iframe;
}