I want it to show the messagebox when i click tab, but it doesn't work. The keycode should be right. But another thing that annoys me, is that if I have that case WM_KEYDOWN there, even if there's nothing in it, the program flashes(my edit boxes and buttons).Code:case WM_KEYDOWN: { switch(wParam){ case 23: MessageBox(hwnd,"You clicked daa!","daa",MB_OK | MB_ICONINFORMATION); return 0; } }