1   
2   unit Unit1;
3   
4   interface
5   
6   uses
7     Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;
8   
9   type
10    TForm1 = class(TForm)
11      procedure CDROM_Notification(var msg : TMessage);
12        message WM_DEVICECHANGE;
13    private
14      { private declarations }
15    public
16      { public declarations }
17    end;
18  
19  var
20    Form1: TForm1;
21  
22  implementation
23  
24  {$R *.DFM}
25  
26  const
27    CD_OUTPUT = $8004;
28    CD_INPUT  = $8000;
29  
30  procedure TForm1.CDROM_Notification(var msg : TMessage);
31  begin
32    if msg.wParam = CD_INPUT then
33      ShowMessage('There is a new CD.')
34    else
35    if msg.wParam = CD_OUTPUT then
36      ShowMessage('CD was ejected.');
37  end;