// if two digit year input dates after this year considered 20 century.
var NUM_CENTYEAR = 30;
// is time input control required by default
var BUL_TIMECOMPONENT = false;
// are year scrolling buttons required by default
var BUL_YEARSCROLL = true;

var calendars = [];
var RE_NUM = /^\-?\d+$/;

function calendar(obj_target) {

	// assigning methods
	this.gen_date = cal_gen_date1;
	this.gen_time = cal_gen_time1;
	this.gen_tsmp = cal_gen_tsmp1;
	this.prs_date = cal_prs_date1;
	this.prs_time = cal_prs_time1;
	this.prs_tsmp = cal_prs_tsmp1;
	this.popup    = cal_popup1;

	// validate input parameters
	if (!obj_target)
		return cal_error("Error calling the calendar: no target control specified");
	if (obj_target.value == null)
		return cal_error("Error calling the calendar: parameter specified is not valid target control");
	this.target = obj_target;
	this.time_comp = BUL_TIMECOMPONENT;
	this.year_scroll = BUL_YEARSCROLL;
	
	// register in global collections
	this.id = calendars.length;
	calendars[this.id] = this;
}

function cal_popup1 (str_datetime) {
	this.dt_current = this.prs_tsmp(str_datetime ? str_datetime : this.target.value);
	if (!this.dt_current) return;

	var obj_calwindow = window.open(
		'calendar.html?datetime=' + this.dt_current.valueOf()+ '&id=' + this.id,
		'Calendar', 'width=200,height='+(this.time_comp ? 215 : 175)+
		',status=no,resizable=no,dependent=yes,alwaysRaised=yes'
	);
	obj_calwindow.opener = window;
	obj_calwindow.focus();
}

// timestamp generating function
function cal_gen_tsmp1 (dt_datetime) {
	return(this.gen_date(dt_datetime) + ' ' + this.gen_time(dt_datetime));
}

// date generating function
function cal_gen_date1 (dt_datetime) {
	return (
		(dt_datetime.getDate() < 10 ? '0' : '') + dt_datetime.getDate() + "-"
		+ (dt_datetime.getMonth() < 9 ? '0' : '') + (dt_datetime.getMonth() + 1) + "-"
		+ dt_datetime.getFullYear()
	);
}
// time generating function
function cal_gen_time1 (dt_datetime) {
	return (
		(dt_datetime.getHours() < 10 ? '0' : '') + dt_datetime.getHours() + ":"
		+ (dt_datetime.getMinutes() < 10 ? '0' : '') + (dt_datetime.getMinutes()) + ":"
		+ (dt_datetime.getSeconds() < 10 ? '0' : '') + (dt_datetime.getSeconds())
	);
}

// timestamp parsing function
function cal_prs_tsmp1 (str_datetime) {
	// if no parameter specified return current timestamp
	if (!str_datetime)
		return (new Date());

	// if positive integer treat as milliseconds from epoch
	if (RE_NUM.exec(str_datetime))
		return new Date(str_datetime);
		
	// else treat as date in string format
	var arr_datetime = str_datetime.split(' ');
	return this.prs_time(arr_datetime[1], this.prs_date(arr_datetime[0]));
}

// date parsing function
function cal_prs_date1 (str_date) {

	var arr_date = str_date.split('-');

	if (arr_date.length != 3) return cal_error ("Invalid date format: '" + str_date + "'.\nFormat accepted is dd-mm-yyyy.");
	if (!arr_date[0]) return cal_error ("Invalid date format: '" + str_date + "'.\nNo day of month value can be found.");
	if (!RE_NUM.exec(arr_date[0])) return cal_error ("Invalid day of month value: '" + arr_date[0] + "'.\nAllowed values are unsigned integers.");
	if (!arr_date[1]) return cal_error ("Invalid date format: '" + str_date + "'.\nNo month value can be found.");
	if (!RE_NUM.exec(arr_date[1])) return cal_error ("Invalid month value: '" + arr_date[1] + "'.\nAllowed values are unsigned integers.");
	if (!arr_date[2]) return cal_error ("Invalid date format: '" + str_date + "'.\nNo year value can be found.");
	if (!RE_NUM.exec(arr_date[2])) return cal_error ("Invalid year value: '" + arr_date[2] + "'.\nAllowed values are unsigned integers.");

	var dt_date = new Date();
	dt_date.setDate(1);

	if (arr_date[1] < 1 || arr_date[1] > 12) return cal_error ("Invalid month value: '" + arr_date[1] + "'.\nAllowed range is 01-12.");
	dt_date.setMonth(arr_date[1]-1);
	 
	if (arr_date[2] < 100) arr_date[2] = Number(arr_date[2]) + (arr_date[2] < NUM_CENTYEAR ? 2000 : 1900);
	dt_date.setFullYear(arr_date[2]);

	var dt_numdays = new Date(arr_date[2], arr_date[1], 0);
	dt_date.setDate(arr_date[0]);
	if (dt_date.getMonth() != (arr_date[1]-1)) return cal_error ("Invalid day of month value: '" + arr_date[0] + "'.\nAllowed range is 01-"+dt_numdays.getDate()+".");

	return (dt_date)
}

// time parsing function
function cal_prs_time1 (str_time, dt_date) {

	if (!dt_date) return null;
	var arr_time = String(str_time ? str_time : '').split(':');

	if (!arr_time[0]) dt_date.setHours(0);
	else if (RE_NUM.exec(arr_time[0]))
		if (arr_time[0] < 24) dt_date.setHours(arr_time[0]);
		else return cal_error ("Invalid hours value: '" + arr_time[0] + "'.\nAllowed range is 00-23.");
	else return cal_error ("Invalid hours value: '" + arr_time[0] + "'.\nAllowed values are unsigned integers.");
	
	if (!arr_time[1]) dt_date.setMinutes(0);
	else if (RE_NUM.exec(arr_time[1]))
		if (arr_time[1] < 60) dt_date.setMinutes(arr_time[1]);
		else return cal_error ("Invalid minutes value: '" + arr_time[1] + "'.\nAllowed range is 00-59.");
	else return cal_error ("Invalid minutes value: '" + arr_time[1] + "'.\nAllowed values are unsigned integers.");

	if (!arr_time[2]) dt_date.setSeconds(0);
	else if (RE_NUM.exec(arr_time[2]))
		if (arr_time[2] < 60) dt_date.setSeconds(arr_time[2]);
		else return cal_error ("Invalid seconds value: '" + arr_time[2] + "'.\nAllowed range is 00-59.");
	else return cal_error ("Invalid seconds value: '" + arr_time[2] + "'.\nAllowed values are unsigned integers.");

	dt_date.setMilliseconds(0);
	return dt_date;
}

function cal_error (str_message) {
	alert (str_message);
	return null;
}


// Valid Date Checker
var dtchk_FormatedDate='';
var strDate='';

function dtchk_chkdate() {
var strDatestyle = "EU";  //European date style
var strDateArray;
var strDay;
var strMonth;
var strYear='';
var intday;
var intMonth;
var intYear;
var booFound = false;
var strSeparatorArray = new Array("-"," ","/",".");
var intElementNr;
var err = 0;
var strMonthArray = new Array(12);
strMonthArray[0] = "01";
strMonthArray[1] = "02";
strMonthArray[2] = "03";
strMonthArray[3] = "04";
strMonthArray[4] = "05";
strMonthArray[5] = "06";
strMonthArray[6] = "07";
strMonthArray[7] = "08";
strMonthArray[8] = "09";
strMonthArray[9] = "10";
strMonthArray[10] = "11";
strMonthArray[11] = "12";

if (strDate.length < 1) {
	return true;
}

for (intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++) {
	if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) {
		strDateArray = strDate.split(strSeparatorArray[intElementNr]);
		if (strDateArray.length != 3) {
			err = 1;
			return false;
		}
		else {
			strDay = strDateArray[0];
			strMonth = strDateArray[1];
			strYear = strDateArray[2];
		}
		booFound = true;
	}
}

if (isNaN(strDay)) {
	err = 1;
	return false;
}

if (isNaN(strYear)) {
	err = 1;
	return false;
}

if (strYear.length < 2) {
	err = 1;
	return false;
}

if (booFound == false) {
	if (strDate.length>5) {
		strDay = strDate.substr(0, 2);
		strMonth = strDate.substr(2, 2);
		strYear = strDate.substr(4);
	}
}

if (strYear.length == 2) {
	strYear = '20' + strYear;
}

if (strYear.length < 4) {
	err = 1;
	return false;
}

// US style
if (strDatestyle == "US") {
	strTemp = strDay;
	strDay = strMonth;
	strMonth = strTemp;
}

intday = parseInt(strDay, 10);
if (isNaN(intday)) {
	err = 2;
	return false;
}

intMonth = parseInt(strMonth, 10);
if (isNaN(intMonth)) {
	for (i = 0;i<12;i++) {
		if (strMonth.toUpperCase() == strMonthArray[i].toUpperCase()) {
			intMonth = i+1;
			strMonth = strMonthArray[i];
			i = 12;
		}
	}
	if (isNaN(intMonth)) {
		err = 3;
		return false;
   }
}

intYear = parseInt(strYear, 10);
if (isNaN(intYear)) {
	err = 4;
	return false;
}

if (intMonth>12 || intMonth<1) {
	err = 5;
	return false;
}
if ((intMonth == 1 || intMonth == 3 || intMonth == 5 || intMonth == 7 || intMonth == 8 || intMonth == 10 || intMonth == 12) && (intday > 31 || intday < 1)) {
	err = 6;
	return false;
}
if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) && (intday > 30 || intday < 1)) {
	err = 7;
	return false;
}
if (intMonth == 2) {
	if (intday < 1) {
	err = 8;
	return false;
}
if (dtchk_LeapYear(intYear) == true) {
	if (intday > 29) {
		err = 9;
		return false;
	}
} else {
	if (intday > 28) {
		err = 10;
		return false;
	}
}

}

if (strDatestyle == "UK") {
	dtchk_FormatedDate = strMonthArray[intMonth-1] + "-" + intday + "-" + strYear;
}
else {
	dtchk_FormatedDate = intday + "-" + strMonthArray[intMonth-1] + "-" + strYear;
}

return true;

}


function dtchk_LeapYear(intYear) {
if (intYear % 100 == 0) {
if (intYear % 400 == 0) { return true; }
}
else {
if ((intYear % 4) == 0) { return true; }
}
return false;
}

function dtchk_DateCheck(s_Date) {

	strDate = s_Date;
	ok = dtchk_chkdate();
	if (ok) {
		return dtchk_FormatedDate;
	} else {
		return '';
	}	

}

function doDateCheck(from, to) {
if (Date.parse(from.value) <= Date.parse(to.value)) {
return true;
}
else {
return false;
   }
}

// Set this function as the clientvalidationfunction for the custom validator
function ValidateDate(objSource,objArgs){
	var ls_Date = document.all(objSource.controltovalidate).value;
	var ls_FormattedDate = dtchk_DateCheck(ls_Date);

	if (ls_FormattedDate != '') {
		document.all(objSource.controltovalidate).value = ls_FormattedDate
		objArgs.IsValid = true;
	} else {
		objArgs.IsValid = false;
	}
}