I'm developing an application with Xlib, and I'd like to make sure it appears on all desktops (it's alot like a panel). Here's the code I have to do it so far:

  Atom desktopAtom;
  unsigned long data[1];

  desktopAtom = XInternAtom(display, "_NET_WM_DESKTOP(CARDINAL)", False);
  data[0] = 0xffffffff;
  XChangeProperty(display, window, desktopAtom, desktopAtom, 32,     
                          PropModeReplace, data, 1);
For some reason or another, this doesn't work. Could anyone please give me a hand?