function openCalendar(sector, dayControlName, monthControlName, url)
	{
		if ( window.calendarWindow && ! calendarWindow.closed )
		{
			calendarWindow.focus();
		}
		else
		{
			document.skyForm.month_selected.value
				= eval('document.skylightsForm.' + monthControlName + '.selectedIndex');
			document.skyForm.sector.value 	= sector;
			document.skyForm.dayControl.value 	= dayControlName;
			document.skyForm.monthControl.value 	= monthControlName;
			calendarWindow 	= window.open(url,"calendar","width=250,height=251,toolbar=0,status=0,location=0,menubar=0,scrollbars=0,resizable=0");
		}
	}