protected void Button1_Click(object sender, EventArgs e)
        {
            string login = txt_login.Text;
            string pass = Scripts.Cryptography.GetMd5Hash(txt_pass.Text);

            ServiceUser.UserClient user = new ServiceUser.UserClient();
            bool f = user.loginUser(login,pass);

               lbl_valido.Text = (f)?"login e password válidos":"login e password inválidos";
               lbl_valido.ForeColor = (f)?Color.Green:Color.Red;
        }