Wie geht das denn?

Hier mein Code:

void __fastcall TFMain::BitBtn1Click(TObject *Sender)
{
	//Login eines Users

	DM1->Q_login->Parameters->CreateParameter("P_username", ftString, pdInput, 10, NULL);
	DM1->Q_login->Parameters->CreateParameter("P_passwort", ftString, pdInput, 10, NULL);

	DM1->Q_login->Parameters->ParamByName("P_username")->Value = Edit1->Text;
	DM1->Q_login->Parameters->ParamByName("P_passwort")->Value = Edit2->Text;

		DM1->Q_login->Close();
		DM1->Q_login->SQL->Clear();
		DM1->Q_login->SQL->Add("select benutzername, passwort from t_user where benutzername = :P_username AND passwort = :P_passwort");
		DM1->Q_login->Open();

			if (DM1->Q_login->RecordCount != 0) {
			   FTerminal->Visible = true;
				this->Visible =  false;
			}
			else
				MessageDlg("Falsche Daten...",mtError ,TMsgDlgButtons() << mbOK ,0);

}