function openWindow(url, name, w, h, x, y) {
	if(window.name == name) {
		if(url) window.location.href = url;
		return true;
	}
	screenw = screen.availWidth - 10;
	screenh = screen.availHeight - 36;
	if(w > screenw) w = screenw;
	if(h > screenh) h = screenh;
	if((x == null) || (y == null) || (x < 0) || (y < 0) || (x > screenw - w) || (y > screenh - h)) {
		x = (screenw - w) / 2;
		y = (screenh - h) / 2;
	}
	popupWin = window.open(url, name, 'width='+w+',height='+h+',left='+x+',top='+y+',titlebar=no,toolbars=no,location=no,menubar=no,status=no,statusbar=no,scrollbars=no,resizable=no');
	popupWin.focus();
}

function rec_calendar_change() {
	var month = document.forms.calendar.month.value;
	var year = document.forms.calendar.year.value;
	var calendar = document.getElementById('calendar_item_' + year + '_' + month);
	if (rec_calendar_current) rec_calendar_current.style.display = 'none';
	if (calendar) {
		calendar.style.display = 'block';
		rec_calendar_current = calendar;
	} else {
		rec_calendar_current = null;
	}
}