file控件文件大小

/// 给上传空间添加默认的路径

function intionFilePath()

{

　　var objFile=document.getElementsByTagName('input')[0];
   　var WshShell=new ActiveXObject("WScript.Shell");
　　objFile.focus();
　　WshShell.SendKeys("C:\\abc.txt");

}

/// 判断文件大小

  $("#Submit").click(function () {
            errMsg = "";
            $(":file").each(function () {

                var obj_file = $(this)[0];
                var filepath = $(this).val();

                if (filepath == "") {
                    errMsg = "请选择上传文件";
                    return;
                }
                //
                var extStart = filepath.lastIndexOf(".");
                var ext = filepath.substring(extStart, filepath.length).toUpperCase();
                if (ext != ".BMP" && ext != ".PNG" && ext != ".GIF" && ext != ".JPG" && ext != ".JPEG" && ext != ".DOCX" && ext != ".DOC" && ext != ".XLSX" && ext != ".XLS" && ext != ".PDF") {
                    errMsg = errMsg + "文件类型限于bmp,png,gif,jpeg,jpg,word,excel格式" + '\r\n';
                    return;
                }
                //
                if (browserCfg.firefox || browserCfg.chrome) {
                    if (obj_file.files[0].size > 0) {
                        if (obj_file.files[0].size > 4 * 1024 * 1024) {
                            errMsg = errMsg + "" + filepath + "超过4M" + '\r\n';
                            return;
                        }
                    }
                }
                if (browserCfg.ie) {
                    try {
                        var obj_img = document.getElementById('FileUpload1').value;
                        var fileSystem = new ActiveXObject("Scripting.FileSystemObject");
                        var file = fileSystem.GetFile(obj_img);
                        fileSize = file.Size;
                        if (fileSize > maxsize) {
                            msg = msg + "" + filepath + "超过4M" + '\r\n';
                            return;
                        }
                    }
                    catch (ex) {
                        return;
                    }
                }


                // $('form').submit();
            });
            if (errMsg.length > 0) {
                alert(errMsg);
                msg = "";
                return;
            }
            //
            boxmessage.loading("正在处理，请稍后...");
            $('form').submit();

        });