function    YYYYMMDDstart()   
   {   
           MonHead    =    [31,    28,    31,    30,    31,    30,    31,    31,    30,    31,    30,    31];   
    
           //先给年下拉框赋内容   
           var    y        =    new    Date().getFullYear();   
           for    (var    i    =    (y-100);    i    <    (y+10);    i++)    //以今年为准，前30年，后30年   
                   document.aspnetForm.YYYY.options.add(new    Option(i,    i));   
    
           //赋月份的下拉框   
           for    (var    i    =    1;    i    <    13;    i++)   
                   document.aspnetForm.MM.options.add(new    Option(i,    i));   
           
           document.aspnetForm.YYYY.value    =    document.aspnetForm.txtyear.value;   
           document.aspnetForm.MM.value    =    document.aspnetForm.txtmonth.value;   
           var    n    =    MonHead[new    Date().getMonth()];   
           if    (new    Date().getMonth()    ==1    &&    IsPinYear(YYYYvalue))    n++;   
                   writeDay(n);    //赋日期下拉框Author:meizz   
           document.aspnetForm.DD.value    =    document.aspnetForm.txtdate.value;   
   }   
   if(document.attachEvent)   
       window.attachEvent("onload",    YYYYMMDDstart);   
   else   
       window.addEventListener('load',    YYYYMMDDstart,    false);   
   function    YYYYDD(str)    //年发生变化时日期发生变化(主要是判断闰平年)   
   {   
           var    MMvalue    =    document.aspnetForm.MM.options[document.aspnetForm.MM.selectedIndex].value;   
           if    (MMvalue    ==    ""){    var    e    =    document.aspnetForm.DD;    optionsClear(e);    return;}   
           var    n    =    MonHead[MMvalue    -    1];   
           if    (MMvalue    ==2    &&    IsPinYear(str))    n++;   
                   writeDay(n)   
   }   
   function    MMDD(str)      //月发生变化时日期联动   
   {   
           var    YYYYvalue    =    document.aspnetForm.YYYY.options[document.aspnetForm.YYYY.selectedIndex].value;   
           if    (YYYYvalue    ==    ""){    var    e    =    document.aspnetForm.DD;    optionsClear(e);    return;}   
           var    n    =    MonHead[str    -    1];   
           if    (str    ==2    &&    IsPinYear(YYYYvalue))    n++;   
                   writeDay(n)   
   }   
   function    writeDay(n)      //据条件写日期的下拉框   
   {   
           var    e    =    document.aspnetForm.DD;    optionsClear(e);   
           for    (var    i=1;    i<(n+1);    i++)   
                   e.options.add(new    Option(i,    i));   
   }   
   function    IsPinYear(year)//判断是否闰平年   
   {        return(0    ==    year%4    &&    (year%100    !=0    ||    year%400    ==    0));}   
   function    optionsClear(e)   
   {   
           e.options.length    =    1;   
   }   
   //--></script>