private void buttonLogin_Click(object sender, EventArgs e) { if (textBoxUserName.Text == "") { labelUserNameError.Visible = true; } else { labelUserNameError.Visible = false; } if (textBoxPassword.Text == "") { labelPasswordError.Visible = true; } else { labelPasswordError.Visible = false; } if (labelUserNameError.Visible || labelPasswordError.Visible) { MainClass.ShowMessage("Fields with * are mandatory", "Error", "Error"); //Error is the type of message. } else { if (Retrievel.GetUserDetails(textBoxUserName.Text, textBoxPassword.Text)) { HomeScreen obj = new HomeScreen(); MainClass.ShowWindow(obj, this, MDI.ActiveForm); } } }