/* function to calculate the number of days to the specified date
	input year, month (1-12), day(1-31)
*/
function daysto(year, month, day) {
	var target=new Date(year,month-1,day);
	var today=new Date();
	var oneday=1000*60*60*24;
	return Math.ceil((target.getTime()-today.getTime())/(oneday));
}