$("#startdate").change(function(){
		var startVal = $("#startdate").val();
		var str = startVal.replace(/-/g,'/');
    	var d = new Date(str);
    	var oneYear = oneYearPast(d);
    	$("#enddate").val(oneYear);
	})


//一年後的今天的前一天
function oneYearPast(time)
{
	//var time=new Date();
	var year=time.getFullYear()+1;
	var month=time.getMonth()+1;
	var day=time.getDate();
	console.log(month);
	if(month<10){
		month="0"+month;
	}
	
	if(day>1){
		day = day-1;
	}else{
		month = month-1;
		console.log(month);
		if(month<10){
			month="0"+month;
		}
		if(month==0){
			month = 12;
		}
		day=new Date(year,month,0).getDate();
	}
	
	var v2=year+'-'+month+'-'+day;
	return v2;		
}