Procedure SetShape(Shape:Pointer)

    Shape must point to valid  BGI  PGUI  mouse  shape data as defined by
    BGIMouseShape.

    This sets  the  mouse  to  Picture  and  uses  mask  Mask.  This only
    works  once  InstallBGIMouse  has  been  called.   Both pointers must
    point  to  data  of  the  GetImage  format  and  must  have  the same
    number of colours as  the  current  mode.   A 16 colour mouse picture
    will not work in a 256 colour mode or a 16.7 million colour mode.

    The picture and mask  may  be  any  size  up  to  32 kb each, a great
    improvement over the 32 byte limit on the standard mouse driver.

    If you assign a new shape  after  setting  a  shape  of your own, you
    must  deallocate  that  space   from   the  heap.   Let  us  say  you
    allocate  a  picture  and  mask  A  on  the  heap.   You  would  call
    SetShape.   You   may   not   deallocate   the   picture   from   the
    heap yet  because  the  mouse  driver  is  using  it.   You then load
    a  new  picture   and   mask   B   on   the   heap.    After  calling
    SetShape  you  must  deallocate   the   heap   space  for  A  as  the
    procedure does not do this for you.

    There are three 16  colour  pictures  and  masks  already defined for
    your use.  These should not be  deallocated  as  they lie in the code
    segment, not the heap.

    Very Important Note

    At present the XHot  and  YHot  are  always  pointing to the top left
    corner.  I'm working on  the  problem.   Make  sure  you set the XHot
    and YHot to 0 for compatibility in the next version.

    I'm trying to implement it  without  trapping all the mouse functions
    using function 9 - but it won't work.  :-(