This message is used by the application to sub-class and change the behavior or appearance of the help window.

param1
     USHORT  controlres  /*  Res number of the control that was selected. */
     USHORT  usReserve   /*  Reserved value, should be 0. */
     USHORT  usevent     /*  The type of event which has occurred. */

param2
     ULONG   ulhwnd      /*  Window handle of relevant window. */