解决SWFUpload的按钮图片加载慢的问题

// Private: loadFlash replaces the button_placeholder element with the flash movie.
SWFUpload.prototype.loadFlash = function () {
    var targetElement, tempParent;

    // Make sure an element with the ID we are going to use doesn‘t already exist
    if (document.getElementById(this.movieName) !== null) {
        throw "ID " + this.movieName + " is already in use. The Flash Object could not be added";
    }

    // Get the element where we will be placing the flash movie
    targetElement = document.getElementById(this.settings.button_placeholder_id) || this.settings.button_placeholder;

    if (targetElement == undefined) {
        throw "Could not find the placeholder element: " + this.settings.button_placeholder_id;
    }


    // Append the container and load the flash
    tempParent = document.createElement("div");
    tempParent.innerHTML = this.getFlashHTML(); // Using innerHTML is non-standard but the only sensible way to dynamically add Flash in IE (and maybe other browsers)
    //targetElement.parentNode.replaceChild(tempParent.firstChild, targetElement);

    /*解决button显示慢的问题*/
    $(tempParent.firstChild).css("opacity", 0);//偷懒使用jquery来处理opacity浏览器兼容
    targetElement.removeAttribute("id");//必须移除这个id，否则多个swfupload同时存在时会有问题
    targetElement.appendChild(tempParent.firstChild);
    /**/

    // Fix IE Flash/Form bug
    if (window[this.movieName] == undefined) {
        window[this.movieName] = this.getMovieElement();
    }

};