Фильтрация!!!

// вывожу в Combobox названия специальностей
procedure TDisciplinyForm.FormCreate(Sender: TObject);
begin
DataModule1.SpecialnTable.First;
ComboBox1.Items.Clear;
While not DataModule1.SpecialnTable.Eof do
begin
ComboBox1.Items.Add(DataModule1.SpecialnTable.fieldbyname('name').AsString);
DataModule1.SpecialnTable.Next;
end;
ComboBox1.Sorted:=True;
end;
 
procedure TDisciplinyForm.ComboBox1Change(Sender: TObject);
begin
if combobox1.Text='' then
DataModule1.DisciplinaTable.Filtered:=false
else
//DisciplinaTable.Filter:='kod_special=;
DataModule1.DisciplinaTable.Filtered:=true;
exit;
end;

  bSwitchFilter: boolean;
  cFilterValue: string;

procedure TDataModule1.SpecialnTableFilterRecord(DataSet: TDataSet; var Accept: Boolean);
begin
   Accept := not bSwitchFilter or (bSwitchFilter and cFilterValue=DataSet.fieldbyname('name').AsString);
end;

procedure TDisciplinyForm.ComboBox1Change(Sender: TObject);
begin
   bSwitchFilter := (combobox1.Text >'');
   if bSwitchFilter then cFilterValue := combobox1.Text;
   DataModule1.DisciplinaTable.Refresch;    
end;