function setBook_days(oForm, oMonth) {
	var cur = oForm.day.options[oForm.day.selectedIndex].value;
	var num = 31;
	
	if (oMonth == 4 || oMonth == 6 || oMonth == 9 || oMonth == 11) num = 30;
	
	if (oMonth == 2) {							
		var year = oForm.year.options[oForm.year.selectedIndex].value;
		var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
		
		if (!isleap) num = 28;
		else num = 29;
	}
	
	oForm.day.options.length = 0;
	for (var i=0; i<num; i++) {
		oForm.day.options[i] = new Option(i+1,i+1);
		if (i+1 == cur) oForm.day.selectedIndex = i;
	}
}
	
function setBook_months(oForm) {
	var year = oForm.year.options[oForm.year.selectedIndex].value;
	var cur_date = new Date();
	
	oForm.month.options.length = 0;
	
	if (year > cur_date.getYear()) {
		for (var i=0; i<12; i++) oForm.month.options[i] = new Option(getBook_monthName(i+1),i+1);
	} else {
		for (var i=cur_date.getMonth(); i<12; i++) {
			oForm.month.options[i] = new Option(getBook_monthName(i+1),i+1);
		}
	}
}

function getBook_monthName(oMonth) {
	switch (oMonth) {
		case 1:
			return "Jan"; break;
		case 2:
			return "Feb"; break;
		case 3:
			return "Mar"; break;
		case 4:
			return "Apr"; break;
		case 5:
			return "May"; break;
		case 6:
			return "Jun"; break;
		case 7:
			return "Jul"; break;
		case 8:
			return "Aug"; break;
		case 9:
			return "Sep"; break;
		case 10:
			return "Oct"; break;
		case 11:
			return "Nov"; break;
		case 12:
			return "Dec"; break;
	}
}