1   
2   unit Unit1;
3   
4   interface
5   
6   uses
7     Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
8     Dialogs, StdCtrls;
9   
10  type
11    TForm1 = class(TForm)
12      Button1: TButton;
13      OpenDialog1: TOpenDialog;
14      procedure Button1Click(Sender: TObject);
15    private
16      { Private declarations }
17    public
18      { Public declarations }
19    end;
20  
21  var
22    Form1: TForm1;
23  
24  implementation
25  
26  {$R *.dfm}
27  
28  procedure RemoveCDXByte( dbFile : string );
29  const
30    Value: Byte = 0;
31    CDXoffSet = 28;
32  var
33    F: file of Byte;
34    handle: integer;
35    buffer:Char;
36  begin
37  
38    handle := FileOpen( dbFile,fmOpenReadWrite+fmShareExclusive );
39  
40    if( handle > 0 ) then
41     begin
42      try
43         FileSeek( handle,CDXoffSet,0 );
44         FileRead( handle,buffer,1);
45         if ( buffer = #1 ) then //checks if index marker exists
46          begin
47             FileSeek( handle,CDXoffSet,0);
48             buffer := #0;   //sets detach marker file
49             FileWrite( handle,buffer,1 );//writes detach marker in table file
50          end;
51      finally
52         FileClose(handle);
53      end;
54     end;
55  
56  end;
57  
58  
59  procedure TForm1.Button1Click(Sender: TObject);
60  begin
61  if OpenDialog1.Execute then begin
62     RemoveCDXByte( OpenDialog1.FileName);
63  end;
64  
65  end;
66  
67  end.