function updateNights(){
	//var list = document.forms[0].arrivalDay;
	//var arrivalDay = document.value;
	var ad = document.getElementById("arrivalDay");
	var am = document.getElementById("arrivalMonth");
	var ay = document.getElementById("arrivalYear");
	var dd = document.getElementById("departureDay");
	var dm = document.getElementById("departureMonth");
	var dy = document.getElementById("departureYear");
	ad = ad.options[ad.selectedIndex].value;
	am = am.options[am.selectedIndex].value;
	ay = ay.options[ay.selectedIndex].value;
	dd = dd.options[dd.selectedIndex].value;
	dm = dm.options[dm.selectedIndex].value;
	dy = dy.options[dy.selectedIndex].value;
	var nights = document.getElementById("nights");
	var ac = dayCount(Number(ad), Number(am), Number(ay));
	var dc = dayCount(Number(dd), Number(dm), Number(dy));
	var count = Number(dc) - Number(ac);
	nights.value = count;
}

function dayCount(day, month, year) {
	var yd;
	var md = 0;
	var leap;
	yd = Math.floor(365.2425 * year);
	switch(month) {
		case 12: md += 30;
		case 11: md += 31;
		case 10: md += 30;
		case 9: md += 31;
		case 8: md += 31;
		case 7: md += 30;
		case 6: md += 31;
		case 5: md += 30;
		case 4: md += 31;
		case 3: md += 28;
		case 2: md += 31;
	}
	leap = ((year % 4) == 0) && ((year % 100) != 0) || ((year % 400) == 0)
	if(leap && month > 2)
		md += 1;
	return yd + md + day;
}