private void LoginButton_Click(object sender, EventArgs e) { if (textBox1.Text == "") { MessageBox.Show("Please enter a valid ID"); } else { /// String Role=query check if id exists and return his Role String Role = controllerObj.AdminLogin(Int32.Parse(textBox1.Text)); if (Role == "P") { AdminP a = new AdminP(this); a.Show(); } else if (Role == "F") { AdminF a = new AdminF(this); a.Show(); } else if (Role == "C") { AdminC a = new AdminC(this); a.Show(); } else { MessageBox.Show("The entered ID Doesn't have a Role"); } } }