// if two digit year input dates after this year considered 20 century.
var giCentury = 30;

// is time input control required by default
var bTime = false;

// are year scrolling buttons required by default
var bScroll_Year = true;

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

////////////////////////////////////////////////////////////////////////////////
function calendar2( obj_month, obj_day, obj_year )
//
// Description:
//		Sets up the global calendar object.
//
// Notes:
//
//
//
//
{
	//
	// assigne methods
	//
	this.gen_date = cal_gen_date2;
	this.gen_time = cal_gen_time2;
	this.gen_tsmp = cal_gen_tsmp2;
	this.prs_date = cal_prs_date2;
	this.prs_time = cal_prs_time2;
	this.prs_tsmp = cal_prs_tsmp2;
	this.popup    = cal_popup2;

	//
	// validate input parameters
	//
	if ( !obj_month || !obj_day || !obj_year )
	{
		return cal_error( "Error calling the calendar: no target control specified" );
	}

	if ( obj_month.value == null || obj_day.value == null || obj_year.value == null )
	{
		return cal_error("Error calling the calendar: parameter specified is not valid tardet control");
	}

	this.target_month = obj_month;
	this.target_day = obj_day;
	this.target_year = obj_year;

	this.time_comp = bTime;
	this.year_scroll = bScroll_Year;

	//
	// register in global collections
	//
	this.id = calendars.length;

	calendars[ this.id ] = this;

}

////////////////////////////////////////////////////////////////////////////////
function cal_popup2( str_datetime, iX, iY )
//
// Description:
//
//
// Notes:
//
//
//
//
{
	iY = isNaN( iY ) ? 200 : iY;
	iX = isNaN( iX ) ? 300 : iX;

	if ( this.target_month.value == "" ||
		  this.target_day.value == "" ||
		  this.target_year.value == "" )
	{
		var sTemp = "";
	}
	else
	{
		var sTemp = this.target_month.value + "/" +
					   this.target_day.value + "/" +
					   this.target_year.value;
	}

	this.dt_current = this.prs_tsmp( str_datetime ? str_datetime
																 : sTemp );

	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 : 190)+
		',status=no,resizable=no,top=' + ( iY ) +
		',left=' + ( iX ) + ',dependent=yes,alwaysRaised=yes'
	);
	obj_calwindow.opener = window;
	obj_calwindow.focus();
}


////////////////////////////////////////////////////////////////////////////////
function cal_gen_tsmp2( dt_datetime )
//
// Description:
// timestamp generating function
//
//
// Notes:
//
//
//
//
{
	return(this.gen_date(dt_datetime) + ' ' + this.gen_time(dt_datetime));
}

////////////////////////////////////////////////////////////////////////////////
function cal_gen_date2( dt_datetime )
//
// Description:
// date generating function
//
//
// Notes:
//
//
//
//
{
	return (

		(dt_datetime.getMonth() < 9 ? '0' : '') + (dt_datetime.getMonth() + 1) + "/"
		+ (dt_datetime.getDate() < 10 ? '0' : '') + dt_datetime.getDate() + "/"
		+ dt_datetime.getFullYear()
	);
}

////////////////////////////////////////////////////////////////////////////////
function cal_gen_time2( dt_datetime )
//
// Description:
// time generating function
//
//
// Notes:
//
//
//
//
{
	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())
	);
}

////////////////////////////////////////////////////////////////////////////////
function cal_prs_tsmp2( str_datetime )
//
// Description:
// timestamp parsing function
//
//
// Notes:
//
//
//
//
{
	// 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]));
}

////////////////////////////////////////////////////////////////////////////////
function cal_prs_date2( str_date )
//
// Description:
// date parsing function
//
//
// Notes:
//
//
//
//
{
	var arr_date = str_date.split('/');

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

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

	if (arr_date[0] < 1 || arr_date[0] > 12) return alert ("Invalid month value: '" + arr_date[0] + "'.\nAllowed range is 01-12.");
	dt_date.setMonth(arr_date[0]-1);

	if (arr_date[2] < 100) arr_date[2] = Number(arr_date[2]) + (arr_date[2] < giCentury ? 2000 : 1900);
	dt_date.setFullYear(arr_date[2]);

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

	return (dt_date)
}

////////////////////////////////////////////////////////////////////////////////
function cal_prs_time2( str_time, dt_date )
//
// Description:
// time parsing function
//
//
// Notes:
//
//
//
//
{

	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 )
//
// Description:
//
//
// Notes:
//
//
//
//
{
	alert (str_message);
	return null;
}