remove for PAM

I have been editing the Delphi source that John handed out with the last release so I could add in removing the drive after exiting.(Like u3) I am getting an error code 5. Could someone with more Delphi knowledge help?

Here is the code I added into the imgCloseClick event procedure:

var
h: THandle; i: integer;   Drive: String;  dw: dword; bback:Boolean;  errorstr:String; sq:integer;
begin
//This part will eject the drive and exit, but will throw an error if it can't. 
Drive:=  ExtractFileDrive(Application.ExeName);
h:=CreateFile(PChar('\\.\'+Drive), 0, 0, nil,OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if h=INVALID_HANDLE_VALUE then MessageBox(Application.Handle,'invalid','error',MB_APPLMODAL);
bback:=DeviceIOControl(h,{IOCTL_STORAGE_EJECT_MEDIA,$90020}$2d4808	, nil, 0, nil, 0, dw, nil);
i:=GetLastError;   CloseHandle(h);
if i=6  then   errorstr:='Device In Use' else errorstr:='Error Code:'+IntToStr(i);
if bback=false then
begin
MessageBox(Application.Handle,PChar(errorstr),'Error',MB_APPLMODAL);
sq:=MessageBox(Application.Handle,'Still Quit?','quit?',MB_YESNO);
 end
 else
 begin
  bolFadeToExit := true;
  FadeInOut(false);
  end;
    if sq=IDYES then
    begin
  bolFadeToExit := true;
  FadeInOut(false);
    end;
end;