// The following comparators should go inside class Person:	


	/** Comparator for comparing two persons by alphabetical order of name
	 */
	public static class CompareByName implements Comparator
	{
		/** Compare two objects (which must both be Persons) by last name,
		 *	with ties broken by first name
		 *
		 *	@param person1 the first object
		 *	@param person2 the second object
		 *	@return a negative number if person1 belongs before person2 in
		 *			alphabetical order of name; 0 if they are equal; a
		 *			positive number if person1 belongs after person2
		 *
		 *	@exception ClassCastException if either parameter is not a
		 *			   Person object
		 */
		public int compare(Object person1, Object person2)
		{
			int compareByLast = ((Person) person1).getLastName().compareTo(
				((Person) person2).getLastName());
			if (compareByLast != 0)
				return compareByLast;
			else
				return ((Person) person1).getFirstName().compareTo(
					((Person) person2).getFirstName());
		}
		
		/** Compare two objects (which must both be Persons) by name
		 *
		 *	@param person1 the first object
		 *	@param person2 the second object
		 *	@return true if they have the same name, false if they do not
		 *
		 *	@exception ClassCastException if either parameter is not a
		 *			   Person object
		 */
		public boolean equals(Object person1, Object person2)
		{
			return compare(person1, person2) == 0;
		}
	}
	
	/** Comparator for comparing two persons by order of zip code
	 */
	public static class CompareByZip implements Comparator
	{
		/** Compare two objects (which must both be Persons) by zip
		 *
		 *	@param person1 the first object
		 *	@param person2 the second object
		 *	@return a negative number if person1 belongs before person2 in
		 *			order of zip; 0 if they are equal; a positive number if
		 *		    person1 belongs after person2
		 *
		 *	@exception ClassCastException if either parameter is not a
		 *			   Person object
		 */
		public int compare(Object person1, Object person2)
		{
			int compareByZip = ((Person) person1).getZip().compareTo(
				((Person) person2).getZip());
			if (compareByZip != 0)
				return compareByZip;
			else
				return new CompareByName().compare(person1, person2); 
		}
		
		/** Compare two objects (which must both be Persons) by zip
		 *
		 *	@param person1 the first object
		 *	@param person2 the second object
		 *	@return true if they have the same zip, false if they do not
		 *
		 *	@exception ClassCastException if either parameter is not a
		 *			   Person object
		 */
		public boolean equals(Object person1, Object person2)
		{
			return compare(person1, person2) == 0;
		}
	}