Maintain a form centered in screen

Add this line in the private part of the form to capture the message :

Procedure TForm1.FormResize ( Sender : TObject ) ;

Begin

   With Form1 Do

   Begin

      Form1.Left := ( Screen.Width - Width ) Div 2 ;

      Form1.Top := ( Screen.Height - Height ) Div 2 ;

   End ;

End ;