var MONTH_NAMES = new Array('January','February','March','April','May','June','July','August','September','October','November','December','Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');



// ------------------------------------------------------------------

// isDate ( date_string, format_string )

//

// Returns true if date string matches format of format string and

// is a valid date. Else returns false.

//

// It is recommended that you trim whitespace around the value before

// passing it to this function, as whitespace is NOT ignored!

// ------------------------------------------------------------------

function isDate(val,format) {

	var date = getDateFromFormat(val,format);

	if (date == 0) { return false; }

	return true;

	}



// -------------------------------------------------------------------

// compareDates(date1,date1format,date2,date2format)

//   Compare two date strings to see which is greater.

//   Returns:

//   1 if date1 is greater than date2

//   0 if date2 is greater than date1 of if they are the same

//  -1 if either of the dates is in an invalid format

// -------------------------------------------------------------------

function compareDates(date1,dateformat1,date2,dateformat2) {

	var d1 = getDateFromFormat(date1,dateformat1);

	var d2 = getDateFromFormat(date2,dateformat2);

	if (d1==0 || d2==0) {

		return -1;

		}

	else if (d1 > d2) {

		return 1;

		}

	return 0;

	}



// ------------------------------------------------------------------

// formatDate (date_object, format)

//

// Returns a date in the output format specified.

// The format string uses the same abbreviations as in getDateFromFormat()

// ------------------------------------------------------------------

function formatDate(date,format) {

	format = format+"";

	var result = "";

	var i_format = 0;

	var c = "";

	var token = "";

	var y = date.getYear()+"";

	var M = date.getMonth()+1;

	var d = date.getDate();

	var H = date.getHours();

	var m = date.getMinutes();

	var s = date.getSeconds();

	var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;

	// Convert real date parts into formatted versions

	// Year

	if (y.length < 4) {

		y = y-0+1900;

		}

	y = ""+y;

	yyyy = y;

	yy = y.substring(2,4);

	// Month

	if (M < 10) { MM = "0"+M; }

		else { MM = M; }

	MMM = MONTH_NAMES[M-1];

	// Date

	if (d < 10) { dd = "0"+d; }

		else { dd = d; }

	// Hour

	h=H+1;

	K=H;

	k=H+1;

	if (h > 12) { h-=12; }

	if (h == 0) { h=12; }

	if (h < 10) { hh = "0"+h; }

		else { hh = h; }

	if (H < 10) { HH = "0"+K; }

		else { HH = H; }

	if (K > 11) { K-=12; }

	if (K < 10) { KK = "0"+K; }

		else { KK = K; }

	if (k < 10) { kk = "0"+k; }

		else { kk = k; }

	// AM/PM

	if (H > 11) { ampm="PM"; }

	else { ampm="AM"; }

	// Minute

	if (m < 10) { mm = "0"+m; }

		else { mm = m; }

	// Second

	if (s < 10) { ss = "0"+s; }

		else { ss = s; }

	// Now put them all into an object!

	var value = new Object();

	value["yyyy"] = yyyy;

	value["yy"] = yy;

	value["y"] = y;

	value["MMM"] = MMM;

	value["MM"] = MM;

	value["M"] = M;

	value["dd"] = dd;

	value["d"] = d;

	value["hh"] = hh;

	value["h"] = h;

	value["HH"] = HH;

	value["H"] = H;

	value["KK"] = KK;

	value["K"] = K;

	value["kk"] = kk;

	value["k"] = k;

	value["mm"] = mm;

	value["m"] = m;

	value["ss"] = ss;

	value["s"] = s;

	value["a"] = ampm;

	while (i_format < format.length) {

		// Get next token from format string

		c = format.charAt(i_format);

		token = "";

		while ((format.charAt(i_format) == c) && (i_format < format.length)) {

			token += format.charAt(i_format);

			i_format++;

			}

		if (value[token] != null) {

			result = result + value[token];

			}

		else {

			result = result + token;

			}

		}

	return result;

	}

	

	

// ------------------------------------------------------------------

// Utility functions for parsing in getDateFromFormat()

// ------------------------------------------------------------------

function _isInteger(val) {

	var digits = "1234567890";

	for (var i=0; i < val.length; i++) {

		if (digits.indexOf(val.charAt(i)) == -1) { return false; }

		}

	return true;

	}

function _getInt(str,i,minlength,maxlength) {

	for (x=maxlength; x>=minlength; x--) {

		var token = str.substring(i,i+x);

		if (token.length < minlength) {

			return null;

			}

		if (_isInteger(token)) { 

			return token;

			}

		}

	return null;

	}

// ------------------------------------------------------------------

// END Utility Functions

// ------------------------------------------------------------------

	

// ------------------------------------------------------------------

// getDateFromFormat( date_string , format_string )

//

// This function takes a date string and a format string. It matches

// If the date string matches the format string, it returns the 

// getTime() of the date. If it does not match, it returns 0.

// 

// This function uses the same format strings as the 

// java.text.SimpleDateFormat class, with minor exceptions.

// 

// The format string consists of the following abbreviations:

// 

// Field        | Full Form          | Short Form

// -------------+--------------------+-----------------------

// Year         | yyyy (4 digits)    | yy (2 digits), y (2 or 4 digits)

// Month        | MMM (name or abbr.)| MM (2 digits), M (1 or 2 digits)

// Day of Month | dd (2 digits)      | d (1 or 2 digits)

// Hour (1-12)  | hh (2 digits)      | h (1 or 2 digits)

// Hour (0-23)  | HH (2 digits)      | H (1 or 2 digits)

// Hour (0-11)  | KK (2 digits)      | K (1 or 2 digits)

// Hour (1-24)  | kk (2 digits)      | k (1 or 2 digits)

// Minute       | mm (2 digits)      | m (1 or 2 digits)

// Second       | ss (2 digits)      | s (1 or 2 digits)

// AM/PM        | a                  |

//

// Examples:

//  "MMM d, y" matches: January 01, 2000

//                      Dec 1, 1900

//                      Nov 20, 00

//  "m/d/yy"   matches: 01/20/00

//                      9/2/00

//  "MMM dd, yyyy hh:mm:ssa" matches: "January 01, 2000 12:30:45AM"

// ------------------------------------------------------------------

function getDateFromFormat(val,format) {

	val = val+"";

	format = format+"";

	var i_val = 0;

	var i_format = 0;

	var c = "";

	var token = "";

	var token2= "";

	var x,y;

	var now   = new Date();

	var year  = now.getYear();

	var month = now.getMonth()+1;

	var date  = now.getDate();

	var hh    = now.getHours();

	var mm    = now.getMinutes();

	var ss    = now.getSeconds();

	var ampm  = "";

	

	while (i_format < format.length) {

		// Get next token from format string

		c = format.charAt(i_format);

		token = "";

		while ((format.charAt(i_format) == c) && (i_format < format.length)) {

			token += format.charAt(i_format);

			i_format++;

			}

		// Extract contents of value based on format token

		if (token=="yyyy" || token=="yy" || token=="y") {

			if (token=="yyyy") { x=4;y=4; }// 4-digit year

			if (token=="yy")   { x=2;y=2; }// 2-digit year

			if (token=="y")    { x=2;y=4; }// 2-or-4-digit year

			year = _getInt(val,i_val,x,y);

			if (year == null) { return 0; }

			i_val += year.length;

			if (year.length == 2) {

				if (year > 70) {

					year = 1900+(year-0);

					}

				else {

					year = 2000+(year-0);

					}

				}

			}

		else if (token=="MMM"){// Month name

			month = 0;

			for (var i=0; i<MONTH_NAMES.length; i++) {

				var month_name = MONTH_NAMES[i];

				if (val.substring(i_val,i_val+month_name.length).toLowerCase() == month_name.toLowerCase()) {

					month = i+1;

					if (month>12) { month -= 12; }

					i_val += month_name.length;

					break;

					}

				}

			if (month == 0) { return 0; }

			if ((month < 1) || (month>12)) { return 0; }

			// TODO: Process Month Name

			}

		else if (token=="MM" || token=="M") {

			x=token.length; y=2;

			month = _getInt(val,i_val,x,y);

			if (month == null) { return 0; }

			if ((month < 1) || (month > 12)) { return 0; }

			i_val += month.length;

			}

		else if (token=="dd" || token=="d") {

			x=token.length; y=2;

			date = _getInt(val,i_val,x,y);

			if (date == null) { return 0; }

			if ((date < 1) || (date>31)) { return 0; }

			i_val += date.length;

			}

		else if (token=="hh" || token=="h") {

			x=token.length; y=2;

			hh = _getInt(val,i_val,x,y);

			if (hh == null) { return 0; }

			if ((hh < 1) || (hh > 12)) { return 0; }

			i_val += hh.length;

			hh--;

			}

		else if (token=="HH" || token=="H") {

			x=token.length; y=2;

			hh = _getInt(val,i_val,x,y);

			if (hh == null) { return 0; }

			if ((hh < 0) || (hh > 23)) { return 0; }

			i_val += hh.length;

			}

		else if (token=="KK" || token=="K") {

			x=token.length; y=2;

			hh = _getInt(val,i_val,x,y);

			if (hh == null) { return 0; }

			if ((hh < 0) || (hh > 11)) { return 0; }

			i_val += hh.length;

			}

		else if (token=="kk" || token=="k") {

			x=token.length; y=2;

			hh = _getInt(val,i_val,x,y);

			if (hh == null) { return 0; }

			if ((hh < 1) || (hh > 24)) { return 0; }

			i_val += hh.length;

			h--;

			}

		else if (token=="mm" || token=="m") {

			x=token.length; y=2;

			mm = _getInt(val,i_val,x,y);

			if (mm == null) { return 0; }

			if ((mm < 0) || (mm > 59)) { return 0; }

			i_val += mm.length;

			}

		else if (token=="ss" || token=="s") {

			x=token.length; y=2;

			ss = _getInt(val,i_val,x,y);

			if (ss == null) { return 0; }

			if ((ss < 0) || (ss > 59)) { return 0; }

			i_val += ss.length;

			}

		else if (token=="a") {

			if (val.substring(i_val,i_val+2).toLowerCase() == "am") {

				ampm = "AM";

				}

			else if (val.substring(i_val,i_val+2).toLowerCase() == "pm") {

				ampm = "PM";

				}

			else {

				return 0;

				}

			}

		else {

			if (val.substring(i_val,i_val+token.length) != token) {

				return 0;

				}

			else {

				i_val += token.length;

				}

			}

		}

	// If there are any trailing characters left in the value, it doesn't match

	if (i_val != val.length) {

		return 0;

		}

	// Is date valid for month?

	if (month == 2) {

		// Check for leap year

		if ( ( (year%4 == 0)&&(year%100 != 0) ) || (year%400 == 0) ) { // leap year

			if (date > 29){ return false; }

			}

		else {

			if (date > 28) { return false; }

			}

		}

	if ((month==4)||(month==6)||(month==9)||(month==11)) {

		if (date > 30) { return false; }

		}

	// Correct hours value

	if (hh<12 && ampm=="PM") {

		hh+=12;

		}

	else if (hh>11 && ampm=="AM") {

		hh-=12;

		}

	var newdate = new Date(year,month-1,date,hh,mm,ss);

	return newdate.getTime();

	}



function parseDate(val) {

	var preferEuro=(arguments.length==2)?arguments[1]:false;

	generalFormats=new Array('y-M-d','MMM d, y','MMM d,y','y-MMM-d','d-MMM-y','MMM d');

	monthFirst=new Array('M/d/y','M-d-y','M.d.y','MMM-d','M/d','M-d');

	dateFirst =new Array('d/M/y','d-M-y','d.M.y','d-MMM','d/M','d-M');

	var checkList=new Array('generalFormats',preferEuro?'dateFirst':'monthFirst',preferEuro?'monthFirst':'dateFirst');

	var d=null;

	for (var i=0; i<checkList.length; i++) {

		var l=window[checkList[i]];

		for (var j=0; j<l.length; j++) {

			d=getDateFromFormat(val,l[j]);

			if (d!=0) { return new Date(d); }

			}

		}

	return null;

	}