Два ComboBox-a + Access

ADOQuery1.SQL.Text:='SELECT * FROM [МоделиАвтомобилей] WHERE [Марка]='+QuotedSTR(ComboBox1.Text);
ADOQuery1.Open;

procedure TForm6.ComboBox1Change(Sender: TObject);
begin
form6.ComboBox2.Items.Clear;
form6.ComboBox2.Items.BeginUpdate;
form1.adotable2.Active := TRUE;
  while not  form1.adotable2.Eof do begin
    form1.ADOQuery2.SQL.Text:='SELECT * FROM [МоделиАвтомобилей] WHERE [Марка]='+QuotedSTR(ComboBox1.Text);
    form1.ADOQuery2.Open;
    form6.ComboBox2.Items.Add (form1.adotable1.Fields [1].AsString);
    form1.adotable2.Next;
  end;
form6.ComboBox2.Items.EndUpdate;
form6.combobox2.Refresh;
form1.ADOTable2.Active:=false;
form1.ADOTable2.Active:=true;
end;

procedure TForm6.ComboBox1Change(Sender: TObject);
begin
  ComboBox2.Items.Clear;
  form1.ADOQuery2.SQL.Text:='SELECT * FROM [МоделиАвтомобилей] WHERE [Марка]='+QuotedSTR(ComboBox1.Text);
  form1.ADOQuery2.Open;
  while not  form1.ADOQuery2.Eof do
    begin
      ComboBox2.Items.Add (form1.ADOQuery2.Fields [1].AsString);
      form1.ADOQuery2.Next;
    end;
  ComboBox2.ItemIndex:=0;
end;