NAME
    	GfxLookUp -- find a graphics extended node associated with a 
		     given pointer (V36)

   SYNOPSIS
       result = GfxLookUp( pointer );
       d0		    a0

	struct  ExtendedNode *GfxLookUp( void *);

   FUNCTION
	Finds a special graphics extended data structure (if any) associated
	with the pointer to a data structure (eg:  ViewExtra associated with
	a View structure).

   INPUTS
	pointer = a pointer to a data structure which may have an 
		   ExtendedNode associated with it (typically a View ).

   RESULT
	result = a pointer to the  ExtendedNode that has previously been
		 associated with the pointer.
		
   BUGS

   SEE ALSO
	 sc:include/graphics/gfxnodes.h  GfxNew()  GfxFree()  GfxAssociate()