private void btnLogin_Click(object sender, EventArgs e) { if (loginhandler.Authenticate(tbox_Username.Text, tbox_Password.Text)) { User authenticateduser = loginhandler.GetUser(tbox_Username.Text); // ^ Above user is logged in, put Form code below inside this if-statement // Client if (authenticateduser is Client) { Form_MainClient MainScreen = new Form_MainClient(authenticateduser); this.Hide(); tbox_Password.Text = string.Empty; tbox_Username.Text = string.Empty; MainScreen.ShowDialog(); this.Show(); } // Volunteer if (authenticateduser is Volunteer) { Form_MainVolunteer MainScreen = new Form_MainVolunteer(authenticateduser); this.Hide(); tbox_Password.Text = string.Empty; tbox_Username.Text = string.Empty; MainScreen.ShowDialog(); this.Show(); } // Admin if (authenticateduser is Admin) { Form_MainAdmin MainScreen = new Form_MainAdmin(authenticateduser); this.Hide(); tbox_Password.Text = string.Empty; tbox_Username.Text = string.Empty; MainScreen.ShowDialog(); this.Show(); } } }