var months = new Array("一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月");
var daysInMonth = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
var days = new Array("日","一", "二", "三", "四", "五", "六");
var today;

document.writeln("<div id='Calendar' style='position:absolute; z-index:1; visibility: hidden; filter:\"progidXImageTransform.Microsoft.Shadow(direction=135,color=#999999,strength=3)\"'></div>");

function getDays(month, year)
{
        //下面的這段代碼是判斷當前是否是閏年的
        if (1 == month)
                return ((0 == year % 4) && (0 != (year % 100))) || (0 == year % 400) ? 29 : 28;
        else
                return daysInMonth[month];
}

function getToday()
{
        //得到今天的年,月,日
        this.now = new Date();
        this.year = this.now.getFullYear();
        this.month = this.now.getMonth();
        this.day = this.now.getDate();
}

function getStringDay(str)
{
        //得到輸入框的年,月,日
        var str=str.split("-")
       
        this.now = new Date(parseFloat(str[0]),parseFloat(str[1])-1,parseFloat(str[2]));
        this.year = this.now.getFullYear();
        this.month = this.now.getMonth();
        this.day = this.now.getDate();
}

function newCalendar() {
        var parseYear = parseInt(document.all.Year.options[document.all.Year.selectedIndex].value);
        var newCal = new Date(parseYear, document.all.Month.selectedIndex, 1);
        var day = -1;
        var startDay = newCal.getDay();
        var daily = 0;
       
        if ((today.year == newCal.getFullYear()) &&(today.month == newCal.getMonth()))
                day = today.day;
               
        var tableCal = document.all.calendar;
        var intDaysInMonth =getDays(newCal.getMonth(), newCal.getFullYear());
        
        for (var intWeek = 1; intWeek < tableCal.rows.length;intWeek++)
                for (var intDay = 0;intDay < tableCal.rows[intWeek].cells.length;intDay++)
                {
                        var cell = tableCal.rows[intWeek].cells[intDay];
                        if ((intDay == startDay) && (0 == daily))
                                daily = 1;
                               
                        if(day==daily) //今天，調用今天的Class
                        {
                                cell.style.background='#6699CC';
                                cell.style.color='#FFFFFF';
                                //cell.style.fontWeight='bold';
                        }
                        else if(intDay==6) //週六
                                cell.style.color='green';
                        else if (intDay==0) //週日
                                cell.style.color='red';
                       
                        if ((daily > 0) && (daily <= intDaysInMonth))
                        {
                                cell.innerText = daily;
                                daily++;
                        }
                        else
                                cell.innerText = "";
                }
}

function GetDate(InputBox)
{
        var sDate;
        //這段代碼處理鼠標點擊的情況
        if (event.srcElement.tagName == "TD")
                if (event.srcElement.innerText != "")
                {
                        //input获得的日期格式：2007-1-6
                        sDate = document.all.Year.value + "-" + document.all.Month.value + "-" + event.srcElement.innerText;

                        /**input获得的日期格式：2007-01-06
                         *sDate = document.all.Year.value + "-" + (document.all.Month.value.length==2?document.all.Month.value:"0"+document.all.Month.value) + "-" + event.srcElement.innerText;
                        */

                        eval("document.all."+InputBox).value=sDate;
                        HiddenCalendar();
                }
}

function HiddenCalendar()
{
        //關閉選擇窗口
        document.all.Calendar.style.visibility='hidden';
}

function ShowCalendar(InputBox)
{
        var x,y,intLoop,intWeeks,intDays;
        var DivContent;
        var year,month,day;
        //var o=document.getElementById(InputBox);
        var o=InputBox;
        var oid=o.id;
        var thisyear; //真正的今年年份
       
        if(!oid)oid=o.name;
       
        thisyear=new getToday();
        thisyear=thisyear.year;
       
        today = o.value;
        if(isDate(today))
                today = new getStringDay(today);
        else
                today = new getToday();
       
        //顯示的位置
        x=o.offsetLeft;
        y=o.offsetTop;
        while(o=o.offsetParent)
        {
                x+=o.offsetLeft;
                y+=o.offsetTop;
        }
        document.all.Calendar.style.left=x+2;
        document.all.Calendar.style.top=y+20;
        document.all.Calendar.style.visibility="visible";
       
        //下面開始輸出日曆表格(border-color:#9DBAF7)
        DivContent="<table border='0' cellspacing='0' style='border:1px solid #0066FF; background-color:#EDF2FC'>";
        DivContent+="<tr>";
        DivContent+="<td style='border-bottom:1px solid #0066FF; background-color:#C7D8FA'>";
       
        //年
        DivContent+="<select name='Year' id='Year' onChange='newCalendar()' style='font-family:Verdana; font-size:12px'>";
        for (intLoop = thisyear - 100; intLoop < (thisyear + 2); intLoop++)
                DivContent+="<option value= " + intLoop + " " + (today.year == intLoop ? "Selected" : "") + ">" + intLoop + "</option>";
        DivContent+="</select>";
       
        //月
        DivContent+="<select name='Month' id='Month' onChange='newCalendar()' style='font-family:Verdana; font-size:12px'>";
        for (intLoop = 0; intLoop < months.length; intLoop++)
                DivContent+="<option value= " + (intLoop + 1) + " " + (today.month == intLoop ? "Selected" : "") + ">" + months[intLoop] + "</option>";
        DivContent+="</select>";
       
        DivContent+="</td>";
       
        DivContent+="<td style='border-bottom:1px solid #0066FF; background-color:#C7D8FA; font-weight:bold; font-family:Wingdings 2,Wingdings,Webdings; font-size:16px; padding-top:2px; color:#4477FF; cursor:hand' align='center' title='關閉' onClick='javascript:HiddenCalendar()'>S</td>";
        DivContent+="</tr>";
        
        DivContent+="<tr><td align='center' colspan='2'>";
        DivContent+="<table id='calendar' border='0' width='100%'>";
       
        //星期
        DivContent+="<tr>";
        for (intLoop = 0; intLoop < days.length; intLoop++)
                DivContent+="<td align='center' style='font-size:12px'>" + days[intLoop] + "</td>";
        DivContent+="</tr>";
       
        //天
        for (intWeeks = 0; intWeeks < 6; intWeeks++)
        {
                DivContent+="<tr>";
                for (intDays = 0; intDays < days.length; intDays++)
                        DivContent+="<td onClick='GetDate(\"" + oid + "\")' style='cursor:hand; border-right:1px solid #BBBBBB; border-bottom:1px solid #BBBBBB; color:#215DC6; font-family:Verdana; font-size:12px' align='center'></td>";
                DivContent+="</tr>";
        }
        DivContent+="</table></td></tr></table>";

        document.all.Calendar.innerHTML=DivContent;
        newCalendar();
}

function isDate(dateStr)
{
        var datePat = /^(\d{4})(\-)(\d{1,2})(\-)(\d{1,2})$/;
        var matchArray = dateStr.match(datePat);
        if (matchArray == null) return false;
        var month = matchArray[3];
        var day = matchArray[5];
        var year = matchArray[1];
        if (month < 1 || month > 12) return false;
        if (day < 1 || day > 31) return false;
        if ((month==4 || month==6 || month==9 || month==11) && day==31) return false;
        if (month == 2)
        {
                var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
                if (day > 29 || (day==29 && !isleap)) return false;
        }
        return true;
}
</script>
<style type="text/css">
<!--
td,input {
        font-family: Verdana, Arial, Helvetica, sans-serif;
        font-size: 12px;
}
body,td,th {
        font-family: Arial;
}
-->
</style>
</head>

<body>
<form name="form1" method="post" action="">
        <table width="500"  border="0" align="center">
          <tr bgcolor="#FFFFFF">
                  <td align="right">日期：</td>
                  <td><input name="birthday" type="text" id="birthday" title="點擊選擇" onClick="javascript:ShowCalendar(this)" size="20"></td>
          </tr>
          </table>
</form>
</body>
</html>