procedure TForm1.Button1Click(Sender: TObject) ;

  function FuncAvail(dllName, funcName: string; var p: pointer): boolean;

  var

    lib: THandle;

  begin

    result := false;

    p := nil;

    if LoadLibrary(PChar(dllName)) = 0 then exit;

    lib := GetModuleHandle(PChar(dllName)) ;

    if lib <> 0 then

    begin

     p := GetProcAddress(lib, PChar(funcName)) ;

     if p <> nil then Result := true;

    end;

  end;

  var

    BlockInput : function(Block: BOOL): BOOL; stdcall;

  begin

   if FuncAvail('USER32.DLL', 'BlockInput', @BlockInput) then

   begin

    ShowMessage('Your Mouse and Keyboard will be blocked for 5 seconds!') ;

    BlockInput(true) ;

    Sleep(5000) ;

    BlockInput(false) ;

   end;

  end;

end.

{We'll need several global variables}

var

    Form1: TForm1;

    StartButton : hWnd;

    OldBitmap : THandle;

    NewImage : TPicture;

...

{Now, we put this code in the

OnCreate event of the form:}

procedure TForm1.FormCreate(Sender: TObject) ;

begin

  NewImage:=TPicture.create;

  NewImage.LoadFromFile('C:WindowsCircles.BMP') ;

  StartButton := FindWindowEx

                  (FindWindow(

                     'Shell_TrayWnd', nil),

                      0,'Button', nil) ;

   OldBitmap:=SendMessage(StartButton,

                          BM_SetImage, 0,

                          NewImage.Bitmap.Handle) ;

  end;

...

{And this other in the OnDestroy:}

  procedure TForm1.FormDestroy(Sender: TObject) ;

  begin

   SendMessage(StartButton,BM_SetImage,0,OldBitmap) ;

   NewImage.Free;

  end;

unction ColorToHTML(const Color: Graphics.TColor): string;

var

  ColorRGB: Integer;

begin

  ColorRGB := Graphics.ColorToRGB(Color);

  Result := SysUtils.Format(

    '#%0.2X%0.2X%0.2X',

    [Windows.GetRValue(ColorRGB),

    Windows.GetGValue(ColorRGB),

    Windows.GetBValue(ColorRGB)]

  );

end;

function CountFiles(const APath, AWildCard: string): Int64;

var

  ReturnCode: Integer;            // result of FindFirst and FindNext routines

  SearchRec: SysUtils.TSearchRec; // carries info about file search

begin

  Result := 0;

  ReturnCode := SysUtils.FindFirst(

    DirToPath(APath) + AWildCard, SysUtils.faAnyFile, SearchRec

  );

  try

    while ReturnCode = 0 do

    begin

      if not IsFlagSet(SearchRec.Attr, SysUtils.faDirectory) and

        (SearchRec.Name <> '.') and

        (SearchRec.Name <> '..') then

        Inc(Result);

      ReturnCode := SysUtils.FindNext(SearchRec);

      ProcessMessages;

    end;

  finally

    SysUtils.FindClose(SearchRec);

  end;

end;

function ReverseNumber(AValue: Int64): Int64;

begin

  Result := 0;

  while AValue > 0 do

  begin

    Result := (Result * 10) + (AValue mod 10);

    AValue := AValue div 10;

  end;

end;