Function  49h   Free Allocated Memory 
		Frees specified memory blocks 
entry   AH      49h 
	ES      segment address of area to be freed 
return  CF      clear   successful 
		set     AX      error code (7, 9) 
note 1) This call is only valid when freeing memory obtained by function 48h. 
     2) A program should not try to release memory not belonging to it.