jquery无刷新文件上传 解决IE安全性问题

/*
    通用文件上传类
    version 1.00
    code by chenfeng during 2014年6月5日
    link zhaoyunfei9271@163.com

    Demo：
    $("#filepost1").Uploader({////上传控件的ID
        action: "/ajax/uploaderajax.ashx",//上传到服务器的路径 默认：/ajax/uploaderajax.ashx
        params: "action=uploadpic",//特殊参数 随同文件一起提交到后台,以&号分隔 默认：action=uploadpic
        maxsize: 1024 * 500,//文件最大尺寸  默认：500K
        exts: ".jpg|.png|.gif|.jpeg",//文件格式限制 默认：.jpg|.png|.gif|.jpeg
        callback: function (file, urlpath) { //上传完成之后回调函数 返回 控件实例和文件服务器路径
        }
    });
*/
$(function () {
    var Uploader = function (file, options) {
        var defaults = {
            action: "/ajax/uploaderajax.ashx",
            params: "action=uploadpic",
            maxsize: 1024 * 500,
            exts: ".jpg|.png|.gif|.jpeg",
            callback: function (fileid, urlpath) { }
        };
        if (options == "remove") {
            Uploader.Remove(file);
            return;
        }
        var opts = $.extend(defaults, options);
        var params = opts.params.split("&");
        var form = $(‘<form action="‘ + opts.action + ‘" enctype="multipart/form-data" method="post" target="ifr_‘ + $(file).attr("id") + ‘" name="form_‘ + $(file).attr("id") + ‘" id="form_‘ + $(file).attr("id") + ‘" style="display: none;"/>‘);
        for (var i = 0; i < params.length; i++) {
            var values = params[i].split("=");
            $(form).append(‘<input type="hidden" name="‘ + values[0] + ‘" value="‘ + values[1] + ‘"/>‘);
        }
        var iframe = $(‘<iframe name="ifr_‘ + $(file).attr("id") + ‘" id="ifr_‘ + $(file).attr("id") + ‘" style="position: absolute; top: -999px;"></iframe>‘);
        $(file).change(function (e) {
            if ($(this).val() != "" && $(this) != undefined) {
                if (!Uploader.BeforeCheck(file, opts)) {
                    return;
                }
                var pfile = $(this).parent();
                $(form).append($(this));
                $(form).submit();
                $(pfile).append($(this));
            }
        });
        $(iframe).load(function () {
            var contents = $(this).contents().get(0);
            var data = $(contents).find(‘body‘).html();
            if (data == "") { return; }
            data = window.eval(‘(‘ + data + ‘)‘);
            if (data.code != 200) {
                alert(data.message);
                return;
            }
            var picUrl = data.data.path;
            opts.callback(file, picUrl);
        });
        $("body").append(form);
        $("body").append(iframe);

    }
    Uploader.BeforeCheck = function (file, opts) {
        var fileName = "";
        var f = null;
        if ($.browser.msie) {
            f = document.getElementById($(file).attr("id"));
        }
        else {
            f = document.getElementById($(file).attr("id")).files[0];
        }
        if (!$.browser.msie && f.size > opts.maxsize) {
            alert(Uploader.ErrorTip.MaxSize);
            return false;
        }
        fileName = $(file).val();
        var exts = opts.exts.split("|");
        var isExt = false;
        for (var i = 0; i < exts.length; i++) {
            if (fileName.indexOf(exts[i]) >= 0) {
                isExt = true;
                break;
            }
        }
        if (!isExt) {
            alert(Uploader.ErrorTip.Ext);
            return false;
        }
        return true;
    }
    Uploader.ErrorTip = {
        MaxSize: "文件超过尺寸",
        Ext: "文件格式错误"
    }
    Uploader.Remove = function (file) {
        $(file).remove()
        $("#form_" + $(file).attr("id")).remove();
        $("#ifr_" + $(file).attr("id")).remove();
    }
    $.fn.Uploader = function (options) {
        return new Uploader(this, options);
    }
})