javascript日期選擇器

         //begin dateSelector
        

document.write("<DIV id='cc' style='BORDER-RIGHT: #000000 1px solid; PADDING-RIGHT: 12px; BORDER-TOP: #000000 1px solid; PADDING-LEFT: 12px; Z-INDEX: 2; BACKGROUND: #ffffff; FILTER: Alpha(opacity=85); LEFT: 505px; VISIBILITY: hidden; PADDING-BOTTOM: 12px; BORDER-LEFT: #000000 1px solid; WIDTH: 260px; LINE-HEIGHT: 22px; PADDING-TOP: 12px; BORDER-BOTTOM: #000000 1px solid; POSITION: absolute; TOP: 419px; HEIGHT: 260px'></DIV>");
document.write("<style>td {font-family: Arial, Helvetica, sans-serif;font-size: 12px;}table{border-collapse:collapse} .sel{font-family: Webdings;font-size: 9pt;font-weight: bold;color: #243F65;cursor:hand;text-decoration: none; background-color:DEDEEF}body {margin-left:0px;margin-top: 0px;}</style>")
 var name;
 function dateSelect(objname){
   cc.style.visibility="visible";
   cc.style.filter="Alpha(opacity=85)"
   cc.style.left=document.body.scrollLeft+window.event.clientX+2;
   cc.style.top=document.body.scrollTop+window.event.clientY+2;
   name = objname;
   showSelect();
 }
 function hiddeninfo(){
   cc.style.visibility="hidden";
 }
 function RunNian(The_Year){
   if ((The_Year%400==0) || ((The_Year%4==0) && (The_Year%100!=0)))
     return true;
   else
     return false;
 }
 function GetWeekday(The_Year,The_Month)
  {
    var Allday;
    Allday = 0;
    if (The_Year>2000){
     for (i=2000 ;i<The_Year; i++){
      if (RunNian(i)) {
      Allday += 366;
     }else {
      Allday += 365;
     }
    }
      for (i=2; i<=The_Month; i++){
        switch (i){
      case 2 :
        if (RunNian(The_Year))
          Allday += 29;
        else
          Allday += 28;
        break;
      case 3 : Allday += 31; break;
      case 4 : Allday += 30; break;
      case 5 : Allday += 31; break;
      case 6 : Allday += 30; break;
      case 7 : Allday += 31; break;
      case 8 : Allday += 31; break;
      case 9 : Allday += 30; break;
      case 10 : Allday += 31; break;
      case 11 : Allday += 30; break;
      case 12 :  Allday += 31; break;
    }
   }
  }
  return (Allday+6)%7;
 }
 function chooseday(The_Year,The_Month,The_Day){
    var Firstday;
    var completely_date;
    if (The_Day!=0)
    completely_date = The_Year + "-" + The_Month + "-" + The_Day;
    else
    completely_date = "";
    //showdate 只是一個爲了顯示而採用的東西，
    //如果外部想引用這裏的時間，可以通過使用 completely_date引用完整日期
    //也可以通過The_Year,The_Month,The_Day分別引用年，月，日
    //當進行月份和年份的選擇時，認爲沒有選擇完整的日期
    Firstday = GetWeekday(The_Year,The_Month);
    ShowCalender(The_Year,The_Month,The_Day,Firstday);
 }
 function chooses(The_Year,The_Month,The_Day){
  var obj2 = document.getElementById(name);
   var Firstday;
   var completely_date;
   var objDate=new Date();
   The_Month=parseInt(The_Month)<10?("0"+The_Month):The_Month;
      The_Day=parseInt(The_Day)<10?("0"+The_Day):The_Day;
     completely_date = The_Year + "-" + The_Month + "-" + The_Day;
   obj2.value = completely_date;  
   hiddeninfo();
  }
 function nextmonth(The_Year,The_Month){
   if (The_Month==12)
     chooseday(The_Year+1,1,0,name);
   else
     chooseday(The_Year,The_Month+1,0,name);
 }
 function prevmonth(The_Year,The_Month){
     var objDate=new Date();  
   if (The_Month==1)  //屏蔽以前月份
     chooseday(The_Year-1,12,0);
   else
     chooseday(The_Year,The_Month-1,0);
 }
 function prevyear(The_Year,The_Month){
     var objTodayDate=new Date();
    chooseday(The_Year-1,The_Month,0);

 }
 function nextyear(The_Year,The_Month){
   chooseday(The_Year+1,The_Month,0);
 }
 function ShowCalender(The_Year,The_Month,The_Day,Firstday){
   var ycdate="";
   var showstr;
   var Month_Day;
   var ShowMonth;
   var today;
   today = new Date();
   switch (The_Month){
     case 1 : ShowMonth = "1月"; Month_Day = 31; break;
     case 2 :
       ShowMonth = "2月";
       if (RunNian(The_Year))
      Month_Day = 29;
       else
      Month_Day = 28;
       break;
     case 3 : ShowMonth = "3月"; Month_Day = 31; break;
     case 4 : ShowMonth = "4月"; Month_Day = 30; break;
     case 5 : ShowMonth = "5月"; Month_Day = 31; break;
     case 6 : ShowMonth = "6月"; Month_Day = 30; break;
     case 7 : ShowMonth = "7月"; Month_Day = 31; break;
     case 8 : ShowMonth = "8月"; Month_Day = 31; break;
     case 9 : ShowMonth = "9月"; Month_Day = 30; break;
     case 10 : ShowMonth = "10月"; Month_Day = 31; break;
     case 11 : ShowMonth = "11月"; Month_Day = 30; break;
     case 12 : ShowMonth = "12月"; Month_Day = 31; break;
   }
  showstr = "";
  showstr = "<Table cellpadding=0 cellspacing=0 border=1 bordercolor=#C0D0E8 width=95% align=center valign=top>"; //上邊框顏色
  showstr +=  "<tr><td width=0 class='sel' οnclick=prevyear("+The_Year+"," + The_Month + ")>3</td><td width=0>&nbsp;&nbsp;&nbsp;" + The_Year + "年&nbsp;</td><td width=0 οnclick=nextyear("+The_Year+","+The_Month+") class='sel'>4</td><td width=0 class='sel' οnclick=prevmonth("+The_Year+","+The_Month+")>3</td><td width=40 align=center>" + ShowMonth + "</td><td width=0 οnclick=nextmonth("+The_Year+","+The_Month+") class='sel'>4</td></tr>";
  showstr +=  "<tr><td align=center width=100% colspan=6>";
  showstr +=  "<table cellpadding=0 cellspacing=0 border=1 bordercolor=#C0D0E8 width=100%>";//內邊框顏色
  showstr += "<Tr align=center bgcolor=#C0D0E8> ";//星期td背景
  showstr += "<td><strong><font color=#ff0000>日</font></strong></td>";
  showstr += "<td><strong><font color=#000000>一</font></strong></td>";
  showstr += "<td><strong><font color=#000000>二</font></strong></td>";
  showstr += "<td><strong><font color=#000000>三</font></strong></td>";
  showstr += "<td><strong><font color=#000000>四</font></strong></td>";
  showstr += "<td><strong><font color=#000000>五</font></strong></td>";
  showstr += "<td><strong><font color=#ff0000>六</font></strong></td>";
   showstr += "</Tr><tr>";
  for (i=1; i<=Firstday; i++)
     showstr += "<Td align=center bgcolor=#ffffff>&nbsp;</Td>";//月前空日日期背景
  for (i=1; i<=Month_Day; i++){
    if ((The_Year==today.getYear()) && (The_Month==today.getMonth()+1) && (i==today.getDate())){
      bgColor = "#DEDEEF";//當前日期td顏色
      ycdate = "<b><font color='#ff0000'>" + i + "</font></b>";
     }else{
      bgColor = "#DEDEEF";//大部分td顏色
      ycdate=i+"";
       }
    if (The_Day>=i ) bgColor = "#ffffff";//選擇日期td顏色
      showstr += "<td align=center bgcolor=" + bgColor + " style='cursor:hand' οnclick=chooses(" + The_Year + "," + The_Month + "," + i + ")>" + ycdate + "</td>";
     Firstday = (Firstday + 1)%7;
     if ((Firstday==0) && (i!=Month_Day)) showstr += "</tr><tr>";
     }
   if (Firstday!=0) {
     for (i=Firstday; i<7; i++)
       showstr += "<td align=center bgcolor=#ffffff>&nbsp;</td>";//月尾空日td背景
      showstr += "</tr>";
    }
    var MyDate=new Date();
    var strTodayDate="<center>今天:"+MyDate.getYear()+"年"+MyDate.getMonth()+"月"+MyDate.getDate()+"日</center>";
   
showstr += "</tr></table></td></tr><tr><td colspan='7'>"+strTodayDate+"<div  align='center' οnclick='hiddeninfo()' style='cursor:hand'>關閉</div></td></tr></table>";
   cc.innerHTML = showstr;
 }
  function showSelect(name){
  var The_Year,The_Day,The_Month;
  var today;
  var Firstday;
  today = new Date();
  The_Year = today.getYear();
  The_Month = today.getMonth() + 1;
  The_Day = today.getDate();
  Firstday = GetWeekday(The_Year,The_Month);
  ShowCalender(The_Year,The_Month,The_Day,Firstday);
 }
         //end dateSelector