def returnValue(self, key, last=False):
        '''Return the key's value for the first entry in the current list.
        If 'last=True', then the last entry is referenced."
        Returns None is the list is empty or the key is missing.
        Example of use:
        >>> test = [
        ...    {"name": "Jim",   "age": 18, "income": 93000, "order": 2},
        ...    {"name": "Larry", "age": 18,                  "order": 3},
        ...    {"name": "Joe",   "age": 20, "income": 15000, "order": 1},
        ...    {"name": "Bill",  "age": 19, "income": 29000, "order": 4},
        ... ]
        >>> print PLOD(test).returnValue("name")
        Jim
        >>> print PLOD(test).sort("name").returnValue("name", last=True)
        Larry
        >>> print PLOD(test).sort("name").returnValue("income", last=True)
        None
        :param last:
           If True, the last entry is used rather than the first.
        :return:
           A value, or None if the list is empty or the key is missing.
        '''
        row = self.returnOneEntry(last=last)
        if not row:
            return None
        dict_row = internal.convert_to_dict(row)
        return dict_row.get(key, None)