#1 Burning Software

procedure TfmMainForm.OnBurn(Sender: TObject);
var
  p_device: ^TDeviceStruct;
begin
  p_device := m_working_thread.GetDevices[m_cbDrives.ItemIndex];
  if not p_device.isBlank then
    if MessageDlg('Disc is not blank. You cannot use it.' + #10#13 +
      'Do you want to erase it?', mtWarning, [mbYes, mbNo], 0, mbYes) = mrYes then
    begin
      with TfmDiskEraser.Create(Application) do ShowModal;
      _IsValidDevice;
    end;

  if _IsValidDevice <> True then
  begin
    ShowMessage('_IsValidDevice<>True');
  end
  else
    if _IsValidFiles <> True then
    begin
      ShowMessage('_IsValidFiles<>True');
    end
    else
      _Burn();
end;

function TfmMainForm._IsValidDevice(): Boolean;
var
  p_device: ^TDeviceStruct;
begin
  p_device := m_working_thread.GetDevices[m_cbDrives.ItemIndex];

  if (p_device.disctype <> DISC_TYPE_CDR) and
    (p_device.disctype <> DISC_TYPE_CDRW) then
  begin
    Result := False;
    Application.MessageBox('You must use CDR or CDRW discs only', 'Warning', MB_OK);
    Exit;
  end;

  if not p_device.isBlank then
  begin
    Result := False;
    Application.MessageBox('Disc is not blank. You cannot use it', 'Warning', MB_OK);
    Exit;
  end;

  if not p_device.isWritable then
  begin
    Result := False;
    Application.MessageBox('Disc is not writable. You cannot use it', 'Warning', MB_OK);
    Exit;
  end;

  Result := True;
end;

Application.MessageBox('Disc is not blank. You cannot use it', 'Warning', MB_OK);

Application.MessageBox('Disc is not blank. You cannot use it', 'Warning', MB_OK);