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
	graphics/gfxnodes.h GfxNew() GfxFree() GfxAssociate()