private void Agregar_Click(object sender, EventArgs e)
 {
     if (string.IsNullOrEmpty(mtbName.Text) | string.IsNullOrEmpty(mtbPass.Text))
     {
         MessageBox.Show("Debe de ingresar Nombre y Password.");
         return;
     }
     else
     {
         string pass = encript.ComputeHash(mtbPass.Text, "SHA512", null);
         DM.InsertUser(mtbName.Text, pass);
         //label8.Visible = true;
         //label8.Text = "Usuario Agregado";
         mtbName.Text = "";
         mtbPass.Text = "";
     }
 }