protected void Button1_Click(object sender, EventArgs e)
        {
            SQLTrans.CrudServiceClient client = new SQLTrans.CrudServiceClient();
            DataSet ds   = client.sp_ValidarUsuario(txtUser.Text, txtPass.Text);
            string  user = "";

            if (ds.Tables[0].Rows.Count > 0)
            {
                try
                {
                    user = ds.Tables[0].Rows[0][0].ToString();
                }
                catch { }
                if (user != txtUser.Text)
                {
                    Session.Remove("userdata");
                    output.Text = "Usuario o Password incorrectos!";
                }
                else
                {
                    SQLTrans.LoginData linfo = new SQLTrans.LoginData();
                    linfo.USER          = txtUser.Text;
                    linfo.PASS          = txtPass.Text;
                    linfo.isAdmin       = client.isAdmin(linfo.USER);
                    Session["userdata"] = linfo;
                    Response.Redirect("Default.aspx");
                }
            }
        }