function WndProc(hWnd: HWND; uMsg: UINT; wParam: WPARAM;
lParam: LPARAM): LRESULT; stdcall;
begin
  Result := 0;
  case uMsg of
    WM_CREATE:
      begin
        IDLoad := createwindow('BUTTON', 'Load Container',
        WS_VISIBLE or WS_CHILD, 10, 130, 150, 25, hwnd, 0, hInstance,
        nil);
        IDClb := createwindow('BUTTON', 'Save to Clipboard',
        WS_VISIBLE or WS_CHILD, 160, 130, 150, 25, hwnd, 0, hInstance,
        nil);
        IDSav := createwindow('BUTTON', 'Save to File',
        WS_VISIBLE or WS_CHILD, 310, 130, 150, 25, hwnd, 0, hInstance,
        nil);
        IDMemo := CreateWindow('Edit', '',
        WS_VISIBLE or WS_CHILD, 10, 5, 450, 120, hwnd, 0, hInstance,
        nil);
        IDLab := createwindow('Static', 'Test',
        WS_VISIBLE or WS_CHILD, 130, 190, 150, 25, hwnd, 0, hInstance,
        nil);
      end;
    WM_DESTROY:
      begin
        PostQuitMessage(0);
      end;
    WM_COMMAND:
     if hiword(wparam) = BN_CLICKED then
      begin
       Case loword(wparam) of
        IDLoad : MessageBox(hwnd, 'Load Button gedrückt', 'Meldung', 0); //Hier hängts
        IDClb : MessageBox(hwnd, 'Clipboard Button gedrückt', 'Meldung', 0);
        IDSav : MessageBox(hwnd, 'Speichern Button gedrückt', 'Meldung', 0);
        IDMemo : MessageBox(hwnd, 'Memo gedrückt', 'Meldung', 0);
        else
        Result := DefWindowProc(hWnd, uMsg, wParam, lParam);
       end;
  end;
  end;
end;