glutDestroyWindow - destroys the specified window.
void glutDestroyWindow (int win);
glutDestroyWindow destroys the window specified by win and the window's associated OpenGL context, logical colormap (if the window is color index), and overlay and related state (if an overlay has been estab- lished). Any subwindows of destroyed windows are also destroyed by glutDestroyWindow. If win was the current window, the current window becomes invalid ( glutGetWindow will return zero).