/* ars navigandi GmbH */
/* dateSelectors.js */

var monthDays = {1:31, 2:28, 3:31, 4:30, 5:31, 6:30, 7:31, 8:31, 9:30, 10:31, 11:30, 12:31};

function checkDate(namespace) {
	var day = document.getElementById(namespace+'_dateDay').value;
	var month = document.getElementById(namespace+'_dateMonth').value;
	var year = document.getElementById(namespace+'_dateYear').value;

	var isLeapYear = ((year%400 == "0") ? (1) : ((year%100 == "0") ? (0) : ((year%4 == "0") ? (1) : (0))));

	var maxDay = (isLeapYear == 1 && month == 2) ? 29 : monthDays[month];

	var dayOptions = document.getElementById(namespace+'_dateDay').options;

	dayOptions[28].disabled = maxDay >= 29 ? false : true ;
	dayOptions[29].disabled = maxDay >= 30 ? false : true ;
	dayOptions[30].disabled = maxDay >= 31 ? false : true ;
	
	if (day > maxDay ) {
		document.getElementById(namespace+'_dateDay').value = maxDay;
	}
}