<!--
// Copyright (c) 1998 Sudhakar Chandrasekharan (thaths@netscape.com)
// All rights reserved
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; version 2 dated June, 1991.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.

// Thanks to Martin Honnen (Martin.Honnen@sector27.de) for some coding
// tips.

// Funtion to return the type of credit card
function typeOfCard(number) {
	/* 
	//	Card Prefixes
	//
	//	Mastercard	51-55
	//	Visa		4
	//	AmEx		34,37
	//	Discover	6011
	*/

	var firstNumber = number.substring(0,1);
	var firstThreeNumbers = number.substring(0,3);

	if (firstNumber == 4) {
		return "VISA";
	} 

	var firstTwoNumbers = number.substring(0,2);
	if (firstTwoNumbers > 50 && firstTwoNumbers < 56) {
		return "MASTERCARD";
	}

	if (firstTwoNumbers == 34 || firstTwoNumbers == 37) {
		return "AMEX";
	}

	var firstFourNumbers = number.substring(0,4);
	if (firstFourNumbers == 6011) {
		return "DISCOVER";
	}
}

// Function that determines whether a credit card number is valid
// Please note that a valid credit card number is not essentially a
// credit card in good standing.
function isValidCreditCard(number) {
	var total = 0;
	var flag = 0;
	for (var i=(number.length - 1);i>=0; i--) {
		if (flag == 1) {
			var digits = number.charAt(i) * 2;
			if (digits > 9) digits -= 9;
			total += digits;
//			var reminder = digits % 10;
//			var quotient = (digits - reminder) / 10;
//			total = total + parseInt(reminder);
//			total = total + parseInt(quotient);
			flag = 0;
		} else {
			total = total + parseInt(number.charAt(i));
			flag = 1;
		}
	}
	if ((total%10) == 0) {
		return true;
	} else {
		return false;
	}
}
// -->
		function isValidDate(month,year)
		{
			/*
			Purpose: return true if the date is valid, false otherwise

			Arguments: day integer representing day of month
			month integer representing month of year
			year integer representing year

			Variables: TodaysDate - date object
			*/
			
			TodaysDate = new Date();
			//set up a Date object based on the day, month and year arguments
			//javascript months start at 0 (0-11 instead of 1-12)			
			CurrentYear = TodaysDate.getYear();
			currentMonth = TodaysDate.getMonth();
			/*
			Javascript Dates are a little too forgiving and will change the date to a reasonable guess if it's invalid. We'll use this to our advantage by creating the date object and then comparing it to the details we put it. If the Date object is different, then it must have been an invalid date to start with...
			*/
			if(year>CurrentYear)
			    return true;
			else 
			if((month>=(currentMonth+1)) && (year=CurrentYear))
			    return true;
			else
			   return false;
			//return ((month>=(currentMonth+1)) && (year>=CurrentYear));
		}