// months as they appear in the calendar's title
var ARR_MONTHS = ["January", "February", "March", "April", "May", "June",
		"July", "August", "September", "October", "November", "December"];
// week day titles as they appear on the calendar
var ARR_WEEKDAYS = ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"];
// day week starts from (normally 0-Su or 1-Mo)
var NUM_WEEKSTART = 1;
// path to the directory where calendar images are stored. trailing slash req.
var STR_ICONPATH = 'img/';

var re_urlCur = new RegExp('c=(\\-?\\d+)');
var re_urlSel = new RegExp('s=(\\-?\\d+)');
var re_id = new RegExp('id=(\\d+)');

var dt_selected = (re_urlSel.exec(String(window.location))
	? new Date(new Number(RegExp.$1)) : new Date());
var dt_current = (re_urlCur.exec(String(window.location))
	? new Date(new Number(RegExp.$1)) : dt_selected);
var num_id = (re_id.exec(String(window.location))
	? new Number(RegExp.$1) : 0);

var obj_caller = (window.opener ? window.opener.calendars[num_id] : null);

if (obj_caller && obj_caller.year_scroll) {
	// get same date in the previous year
	var dt_prev_year = new Date(dt_current);
	dt_prev_year.setFullYear(dt_prev_year.getFullYear() - 1);
	if (dt_prev_year.getDate() != dt_current.getDate())
		dt_prev_year.setDate(0);
	
	// get same date in the next year
	var dt_next_year = new Date(dt_current);
	dt_next_year.setFullYear(dt_next_year.getFullYear() + 1);
	if (dt_next_year.getDate() != dt_current.getDate())
		dt_next_year.setDate(0);
}

// get same date in the previous month
var dt_prev_month = new Date(dt_current);
if (dt_prev_month.getMonth()) {
	dt_prev_month.setMonth(dt_prev_month.getMonth() - 1);
	if (dt_prev_month.getDate() != dt_current.getDate())
		dt_prev_month.setDate(0);
}
else {
	dt_prev_month.setFullYear(dt_prev_month.getFullYear() - 1);
	dt_prev_month.setMonth(11);
}

// get same date in the next month
var dt_next_month = new Date(dt_current);
dt_next_month.setMonth(dt_next_month.getMonth() + 1);
if (dt_next_month.getDate() != dt_current.getDate())
	dt_next_month.setDate(0);

// get first day to display in the grid for current month
var dt_firstday = new Date(dt_current);
dt_firstday.setDate(1);
dt_firstday.setDate(1 - (7 + dt_firstday.getDay() - NUM_WEEKSTART) % 7);

// function passing selected date to calling window
function set_datetime(n_datetime, b_close) {
	if (!obj_caller) return;

	var dt_datetime = obj_caller.prs_time(
		(document.cal ? document.cal.time.value : ''),
		new Date(n_datetime)
	);

	if (!dt_datetime) return;
	if (b_close) {
		
		obj_caller.target.value = (document.cal
			? obj_caller.gen_tsmp(dt_datetime)
			: obj_caller.gen_date(dt_datetime)
		);window.close();
	}
	else obj_caller.popup(dt_datetime.valueOf());
}