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<br><div>
　　<select ></select>年
   <select ></select>月
   <select ></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();
})