tape backup

how can I write a file over a tape backup
I use the procedure below to get the handle of the tape device, but I
don't know how can I write a file over the tape media. Is there anyone
can help me, please ???
I have found the "write" procedure below but I don' know how can I use
it.
Best regards,
                    Kalbert


//------------------------------------------------------------------------------
// open the tape drive e get the Handle
//------------------------------------------------------------------------------
function TForm1.OpenDrive:THandle;
var
  TapeHandle : THandle;
  Security : TSecurityAttributes;
begin
  Security.nLength := SizeOf(TSecurityAttributes);
  Security.bInheritHandle := FALSE;
  Security.lpSecurityDescriptor := nil;

  TapeHandle := CreateFile(PChar('\\.\TAPE0'),
                           GENERIC_READ OR GENERIC_WRITE,
                           FILE_SHARE_READ OR FILE_SHARE_WRITE,
                           @[EMAIL PROTECTED]
                           OPEN_EXISTING,
                           0,
                           0);

  if TapeHandle=INVALID_HANDLE_VALUE then
    result := 0
  else
    result := TapeHandle;
end;




procedure TForm1.Write(iBuffer:Pointer; iBufLen:DWORD);
var
  TapeHandle  : THandle;
  lBytesWritten : DWord;
begin
  TapeHandle := OpenDrive;

  if not WriteFile(TapeHandle,iBuffer^,iBufLen,lBytesWritten,nil) then
    if lBytesWritten <> iBufLen then
      ShowMessage('WriteFile only wrote '+IntToStr(lBytesWritten)+'
bytes when'+IntToStr(iBufLen)+' bytes were requested')
    else
      raise Exception.Create('WriteFile returned an error, code
was'+IntToStr(GetLastError()));
end;