procedure TfrmTanka.BtnTankaClick(Sender: TObject);
begin
  frmTanka := TfrmTanka.Create(Self);
  if  frmTanka.ShowModal = mrOK  then
  begin
    EditTanka.Text := FormatFloat('#0.00',frmTanka.scTanka);
    BtnOk.SetFocus;
  end
  else
  begin
    EditTanka.SetFocus;
  end;
  frmTanka.Release;
end;