procedure Form1_Edit1_OnExit (Sender: TObject);
begin
  if ValidInt(Form1.Edit1.Text) then
  begin
    if ((StrToInt(Form1.Edit1.Text) < 0) or (StrToInt(Form1.Edit1.Text) > 128)) then
    begin
      ShowHint(Form1.Edit1, 'WRONG VALUE', -1, -1, 5000);
      Form1.ButtonSave.Enabled := False;                      // Disable Save button
    end else Form1.ButtonSave.Enabled := True;                // Enable Save button
  end
  else Showmessage('NOT A NUMBER');
end;