@Override
	public String getMessage()
	{
		switch( error )
		{
			case NULL:
				return "a range intersection returned no cells";
			case DIV0:
				return "attempted to divide by zero";
			case VALUE:
				return "operand type mismatch";
			case REF:
				return "reference to a cell that doesn't exist";
			case NAME:
				return "reference to an unknown function or defined name";
			case NUM:
				return "number storage overflow";
			case NA:
				return "lookup returned no value for the given criteria";
			case CIR_ERR:
				return "circular reference error";
			default:
				return "unknown error occurred";
		}
	}