function getRawTs(year, month, day) {
	return (parseInt(year)-2000)*365 + parseInt(month)*30 + parseInt(day);
}

function addAvailabilityPeriod() {
	with(document.frmApplication) {
		var d = new Date();
		var dateStart = getRawTs(selFromYear.options[selFromYear.selectedIndex].text, selFromMonth.options[selFromMonth.selectedIndex].value, selFromDay.options[selFromDay.selectedIndex].text);
		var dateEnd = getRawTs(selToYear.options[selToYear.selectedIndex].text, selToMonth.options[selToMonth.selectedIndex].value, selToDay.options[selToDay.selectedIndex].text);
		var dateNow = getRawTs(d.getYear()<1900?(1900+d.getYear()):d.getYear(), d.getMonth(), d.getDay());

		if(dateStart <= dateEnd && dateStart > dateNow) {
			var sPeriod = "";
			sPeriod += selFromMonth.options[selFromMonth.selectedIndex].text + " ";
			sPeriod += selFromDay.options[selFromDay.selectedIndex].text + " ";
			sPeriod += selFromYear.options[selFromYear.selectedIndex].text + " ";
			sPeriod += "- ";
			sPeriod += selToMonth.options[selToMonth.selectedIndex].text + " ";
			sPeriod += selToDay.options[selToDay.selectedIndex].text + " ";
			sPeriod += selToYear.options[selToYear.selectedIndex].text;
	        iDestLen = elements['selAvailability[]'].length;
	        elements['selAvailability[]'].options[iDestLen] = new Option(sPeriod, sPeriod);
		} else {
			alert("Invalid availability period!");
		}
	}
}