/**
  * DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
  */
// Declaring valid date character, minimum year and maximum year
var dtCh = '/';
var minYear = 1900;
var maxYear = 2100;

function isInteger(s){
	var i;
	for(i = 0; i < s.length; i++){
		// Check that current character is number.
		var c = s.charAt(i);
		if((c < '0') || (c > '9')){
			return false;
		}
	}
	// All characters are numbers.
	return true;
}

function stripCharsInBag(s, bag){
	var i;
	var returnString = '';
	// Search through string's characters one by one.
	// If character is not in bag, append to returnString.
	for(i = 0; i < s.length; i++){
		var c = s.charAt(i);
		if(bag.indexOf(c) == -1){
			returnString += c;
		}
	}
	return returnString;
}

function daysInFebruary(year){
	// February has 29 days in any year evenly divisible by four,
	// EXCEPT for centurial years which are not also divisible by 400.
	return (((year % 4 == 0) && ((!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28);
}

function DaysArray(n){
	for(var i = 1; i <= n; i++){
		this[i] = 31
		if(i == 4 || i == 6 || i == 9 || i == 11) {this[i] = 30}
		if(i == 2) {this[i] = 29}
	}
	return this
}

function validDate(dtStr){
	var daysInMonth = DaysArray(12)
	var pos1 = dtStr.indexOf(dtCh)
	var pos2 = dtStr.indexOf(dtCh,pos1 + 1)
	var strMonth = dtStr.substring(0, pos1)
	var strDay = dtStr.substring(pos1 + 1, pos2)
	var strYear = dtStr.substring(pos2 + 1)
	strYr = strYear
	if(strDay.charAt(0) == '0' && strDay.length > 1) strDay = strDay.substring(1)
	if(strMonth.charAt(0) == '0' && strMonth.length > 1) strMonth = strMonth.substring(1)
	for(var i = 1; i <= 3; i++){
		if(strYr.charAt(0) == '0' && strYr.length > 1) strYr = strYr.substring(1)
	}
	month = parseInt(strMonth)
	day = parseInt(strDay)
	year = parseInt(strYr)
	if(pos1 == -1 || pos2 == -1){
		errMessages.push('<li>The date format should be : yyyy-mm-dd</li>');
		return false
	}
	if(strMonth.length < 1 || month < 1 || month > 12){
		errMessages.push('<li>Please enter a valid month</li>');
		return false
	}
	if(strDay.length < 1 || day < 1 || day > 31 || (month == 2 && day > daysInFebruary(year)) || day > daysInMonth[month]){
		errMessages.push('<li>Please enter a valid day</li>');
		return false
	}
	if(strYear.length != 4 || year == 0 || year < minYear || year > maxYear){
		errMessages.push('<li>Please enter a valid 4 digit year between ' + minYear + ' and ' + maxYear + '</li>');
		return false
	}
	if(dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		errMessages.push('<li>Please enter a valid date</li>');
		return false
	}
	return true
}

function changeDateFormat(dateStr){
	aDateStr = dateStr.split('/');
	return aDateStr[2] + '-' + aDateStr[0] + '-' + aDateStr[1];
}