js前后五年的时间日期万年历

<script src='bootstrap/js/jquery-1.11.2.min.js'></script>//引入JQUERY文件
<div>
　　<select id="nian"class="bian"></select>年
   <select id="yue"class="bian"></select>月
   <select id="ri"></select>日
</div>

FillYear();
FillYue();
FillTian();
function FillYear(){
	var b = new Date();
	var nian = parseInt(b.getFullYear());
	var str;
	for(var i=nian-5;i<nian+6;i++){
		if(i==nian){
			str = str+"<option selected='selected'>"+i+"</option>";
		}else{
			str = str+"<option>"+i+"</option>";
		}
	}
	document.getElementById("nian").innerHTML = str;

}

function FillYue()
{
	var b = new Date();
	var y = parseInt(b.getMonth()+1);
	var str;
	for(var i=1;i<13;i++)
	{
		if(i==y)
		{
			str = str+"<option selected='selected'>"+i+"</option>";
		}else
		{
			str = str+"<option>"+i+"</option>";
		}
	}
	document.getElementById("yue").innerHTML = str;
}

function FillTian(){
	var b = new Date();
	var r = parseInt(b.getDate());
	var nian = document.getElementById("nian").value;
	var yue = document.getElementById("yue").value;

	ts=31;

	if(yue==4 || yue==6 || yue==9 || yue==11){
		ts=30;
	}
	if(yue==2){
		if((nian%4==0 && nian%100!=0) || nian%400==0){
			ts=29;
		}else{
			ts=28;
		}
	}
	var str;
	for(var i=1;i<ts+1;i++){
		if(i==r){
			str = str+"<option selected='selected'>"+i+"</option>";
		}else{
			str = str+"<option>"+i+"</option>";
		}
	}
	document.getElementById("ri").innerHTML = str;
}
$(".bian").change(function(){
	FillTian();
})