def deleteStoredSms(self, index, memory=None):
        """ Deletes the SMS message stored at the specified index in modem/SIM card memory
        
        :param index: The index of the SMS message in the specified memory
        :type index: int
        :param memory: The memory type to delete from. If None, use the current default SMS read/delete memory
        :type memory: str or None
        
        :raise CommandError: if unable to delete the stored message
        """
        self._setSmsMemory(readDelete=memory)
        self.write('AT+CMGD={0},0'.format(index))