protected void Page_Load(object sender, EventArgs e)
        {
            //Random ran = new Random();
            //int seed = ran.Next(1000);
            //string text = GenerateRandomString(4, RandomStringMode.Mix);
            //Session["ValidateCode"] = text;

            //ShowValidationCode(ref seed, text, 12, Color.Black, Color.White);
            ValidateHelper vhelper = new ValidateHelper();
            string checkCode = vhelper.CreateCode(4);
            Response.Clear();
            Response.ContentType = "image/jpeg";
            CreateImages(checkCode);
            Response.End();
        }