public string GetFileType(string FileDirectory)

        {

            DirectoryInfo DI = new DirectoryInfo(FileDirectory);

            FileSystemInfo[] f = DI.GetFileSystemInfos();

            string Ex="";

            foreach (FileSystemInfo i in f)

            {

                if (i is DirectoryInfo)

                {

                    if ((i.Attributes & FileAttributes.Hidden) == 0)

                    {

                        Search(i.FullName);

                        return null;

                    }



                }

                else

                {

                    if (Ex != "")

                    {

                        Ex = i.Extension;

                        return Ex;

                    }

                    else

                    {

                        Ex = Ex + "," + i.Extension;

                        return Ex;

                    }





                }

            }

            

        }