unit Unit1;
 
 interface
 
 uses
   Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
   StdCtrls;
 
 type
   TForm1 = class(TForm)
     ListBox1: TListBox;
     procedure FormCreate(Sender: TObject);
   private
     { private declarations }
     procedure MyMouseEvent(var Msg: TMsg; var Handled: Boolean);
   public
     { public declarations }
   end;
 
 var
   Form1: TForm1;
 
 implementation
 
 {$R *.DFM}
 
 procedure TForm1.MyMouseEvent(var Msg: TMsg; var Handled: Boolean);
 var
   s : string;
 begin
   case Msg.message of
     wm_LButtonDown: s := 'left mouse down';
     wm_LButtonUp:   s := 'left mouse up';
     wm_MouseMove:   s := 'mouse move';
     else            s := '';
   end;
   if s <> '' then
     ListBox1.Items.Insert(0, s);
 end;
 
 procedure TForm1.FormCreate(Sender: TObject);
 begin
   Application.OnMessage := MyMouseEvent;
 end;
 
 end.