//日历
var use_css = false;
var use_layers = false;
if (document.all)
{
   use_css    = true;
}
if (document.layers)
{
   use_layers = true;

}

var CALWINDOW;

// Write out default styles to document or return string
function writestyles(doc)
{
   var result = "";
   result += "<STYLE>\n";
   result += "TD.cal { font-family:arial; font-size: 8pt; }\n";
   result += "TD.calmonth { font-family:arial; font-size: 8pt; text-align: right;}\n";
   result += "TD.caltoday { font-family:arial; font-size: 8pt; text-align: right; color: white; background-color:#C0C0C0; border-width:1; border-type:solid; border-color:#800000; }\n";
   result += "INPUT.caltoday { font-family:arial; font-size: 8pt; width:47px; height: 20px; }\n";
   result += "A.cal { text-decoration:none; color:#000000; }\n";
   result += "A.calthismonth { text-decoration:none; color:#000000; }\n";
   result += "A.calothermonth { text-decoration:none; color:#808080; }\n";
   result += ".tb_outer { border:solid 1px #808080; }\n";
   result += ".tr_week {font-weight:bold; }\n";
   result += "</STYLE>\n";
   if (doc != "")
   {
      doc.write(result);
   }
   else
   {
      return result;
   }
}
writestyles(this.document);

function getOffsetLeft (el)
{
   var scrollamount = document.body.scrollLeft;
   var ol = el.offsetLeft;
   while ((el = el.offsetParent) != null)
   {
      ol += el.offsetLeft;

   }
   ol = ol - scrollamount;
   return ol;
}
function getOffsetTop (el)
{
   var scrollamount = document.body.scrollTop;
   var ot = el.offsetTop;
   while((el = el.offsetParent) != null)
   {
      ot += el.offsetTop;

   }
   ot = ot - scrollamount;
   return ot;
}
//在需要显示日历的地方调用本函数 divname：日历框 anchorname：在本控件旁出现日历 functionname：自定义的获得日期的函数 如：showBeginDate
function showCalendar(divname, anchorname, functionname)
{
   // Find position relative to anchor
   if (use_css)
   {
      var x = getOffsetLeft(document.all[anchorname]);
      var y = getOffsetTop(document.all[anchorname]);
   }
   else if (use_layers)
   {
      var found = 0;
      for (var i = 0; i < document.anchors.length; i ++ )
      {
         if (document.anchors[i].name == anchorname)
         {
            found = 1;
            break;
         }
      }
      if (found == 0)
      {
         return;
      }
      var x = document.anchors[i].x;
      var y = document.anchors[i].y;
      x = x - window.pageXOffset;
      y = y - window.pageYOffset;
   }
   else
   {
      return;
   }
   x = x - 8;
   y = y + 25;
   // WRITE CALENDAR TO DIV
   if (divname != "")
   {
      // Position the calendar DIV
      if (use_layers)
      {
         var calendardiv = document.layers[divname];

      }
      if (use_css)
      {
         var calendardiv = document.all[divname].style;

      }
      calendardiv.left = x;
      calendardiv.top  = y;
      // Write output to calendar DIV
      if (arguments.length > 4)
      {
         outputCalendar(divname, functionname, arguments[3], arguments[4]);
      }
      else
      {
         outputCalendar(divname, functionname);
      }
      // Show the calendar DIV
      calendardiv.visibility = "visible";
   }
   // WRITE CALENDAR TO POPUP WINDOW
   else
   {
      if (use_layers)
      {
         var windowx = window.screenX;
         var windowy = window.screenY + (window.outerHeight - 24 - window.innerHeight);
      }
      if (use_css)
      {
         var windowx = window.screenLeft;
         var windowy = window.screenTop;
      }
      x = x + windowx;
      y = y + windowy;
      if ( ! CALWINDOW || CALWINDOW.closed)
      {
         CALWINDOW = window.open("about:blank", "calwindow", "status,width=150,height=175,screenX=" + x + ",left=" + x + ",screenY=" + y + ",top=" + y + ",resizable");
      }
      // Write output to popup window
      if (arguments.length > 4)
      {
         outputCalendar(divname, functionname, arguments[3], arguments[4]);
      }
      else
      {
         outputCalendar(divname, functionname);
      }
   }
}

function hideCalendar(divname)
{
   if (divname != "")
   {
      if (use_layers)
      {
         var calendardiv = document.layers[divname];

      }
      if (use_css)
      {
         var calendardiv = document.all[divname].style;

      }
      calendardiv.visibility = "hidden";
   }
   else
   {
      if (CALWINDOW && ! CALWINDOW.closed)
      {
         CALWINDOW.close();
      }
   }
}

function outputCalendar(divname, functionname)
{
   var now = new Date();
   if (arguments.length > 2)
   {
      var month = arguments[2];

   }
   else
   {
      var month = now.getMonth() + 1;

   }
   if (arguments.length > 3)
   {
      var year = arguments[3];

   }
   else
   {
      var year = now.getFullYear();

   }
   var monthnames = new Array('1月', '2月', '3月', '4月', '5月', '6月', '7月', '8月', '9月', '10月', '11月', '12月');
   var daysinmonth = new Array(0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);

   if ( ( (year % 4 == 0) && (year % 100 != 0) ) || (year % 400 == 0) )
   {
      // leap year
      daysinmonth[2] = 29;
   }
   var current_month = new Date(year, month - 1, 1);

   var display_year = year;
   var display_month = month;
   var display_date = 1;

   var offset = 0;
   var weekday = current_month.getDay();
   if (weekday > 0)
   {
      display_month -- ;
      if (display_month < 1)
      {
         display_month = 12;
         display_year -- ;

      }
      display_date = daysinmonth[display_month] - weekday + 1;
   }
   var next_month = month + 1;
   var next_month_year = year;
   if (next_month > 12)
   {
      next_month = 1;
      next_month_year ++ ;

   }
   var last_month = month - 1;
   var last_month_year = year;
   if (last_month < 1)
   {
      last_month = 12;
      last_month_year -- ;

   }

   var date_class;
   var result = "";
   if (divname == "" )
   {
      var windowref = "window.opener.";
   }
   else
   {
      var windowref = "";
   }
   // If POPUP, write entire HTML document
   if (divname == "")
   {
      result += "<HTML><HEAD>" + writestyles('') + "</HEAD><BODY MARGINWIDTH=0 MARGINHEIGHT=0 TOPMARGIN=0 RIGHTMARGIN=0 LEFTMARGIN=0>";
   }
   //result += '<FORM>';
   if (divname != "")
   {
      result += '<TABLE WIDTH=144 class=tb_outer BORDER=1 BORDERCOLOR="#808080" CELLSPACING=0 CELLPADDING=1>';
      result += '<TR><TD ALIGN=CENTER>';
      result += '<CENTER>';
      result += '<TABLE WIDTH=144 BORDER=0 BORDERWIDTH=0 CELLSPACING=0 CELLPADDING=0>';
   }
   else
   {
      result += '<CENTER><TABLE WIDTH=100% BORDER=0 BORDERWIDTH=0 CELLSPACING=0 CELLPADDING=0>';
   }
   result += '<TR BGCOLOR="#c0c0c0">';
   result += ' <TD CLASS="cal" WIDTH=22 ALIGN=CENTER VALIGN=MIDDLE><B><A CLASS="cal" HREF="javascript:'+windowref+'outputCalendar(\''+divname+'\',\''+functionname+'\','+last_month+','+last_month_year+')">&lt;&lt;</A></B></TD>';
   result += ' <TD CLASS="cal" WIDTH=100 ALIGN=CENTER>' + year + '年 ' + monthnames[month - 1] + '</TD>';
   result += ' <TD CLASS="cal" WIDTH=22 ALIGN=CENTER VALIGN=MIDDLE><B><A CLASS="cal" HREF="javascript:'+windowref+'outputCalendar(\''+divname+'\',\''+functionname+'\','+next_month+','+next_month_year+')">&gt;&gt;</A></B></TD>';
   result += '</TR>';
   result += '</TABLE>';
   result += '<TABLE WIDTH=120 BORDER=0 CELLSPACING=1 CELLPADDING=0 ALIGN=CENTER>';
   result += '<TR class=tr_week>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>日</TD>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>一</TD>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>二</TD>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>三</TD>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>四</TD>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>五</TD>';
   result += ' <TD CLASS="cal" ALIGN=RIGHT WIDTH=14%>六</TD>';
   result += '</TR>';
   result += '<TR><TD COLSPAN=7 ALIGN=CENTER><IMG SRC="graypixel.gif" WIDTH=120 HEIGHT=1></TD></TR>';
   for (var row = 1; row <= 6; row ++ )
   {
      result += '<TR>';
      for (var col = 1; col <= 7; col ++ )
      {
         if (display_month == month)
         {
            date_class = "calthismonth";
         }
         else
         {
            date_class = "calothermonth";
         }
         if ((display_month == now.getMonth() + 1) && (display_date == now.getDate()) && (display_year == now.getFullYear()))
         {
            td_class = "caltoday";
         }
         else
         {
            td_class = "calmonth";
         }
         result += ' <TD CLASS="'+td_class+'"><A HREF="javascript:'+windowref+functionname+'('+display_year+','+display_month+','+display_date+');'+windowref+'hideCalendar(\''+divname+'\');" CLASS="'+date_class+'">' + display_date + '</A></TD>';
         display_date ++ ;
         if (display_date > daysinmonth[display_month])
         {
            display_date = 1;
            display_month ++ ;
         }
         if (display_month > 12)
         {
            display_month = 1;
            display_year ++ ;
         }
      }
      result += '</TR>';
   }
   result += '<TR><TD COLSPAN=7 ALIGN=CENTER><IMG SRC="graypixel.gif" WIDTH=120 HEIGHT=1></TD></TR>';
   result += '<TR>';
   result += ' <TD COLSPAN=7 ALIGN=CENTER>';
   result += '  <INPUT CLASS="caltoday" TYPE="button" VALUE="今天" onClick="'+windowref+functionname+'(\''+now.getFullYear()+'\',\''+(now.getMonth()+1)+'\',\''+now.getDate()+'\');'+windowref+'hideCalendar(\''+divname+'\');">';
   result += '&nbsp;&nbsp;&nbsp;<input class="caltoday" onclick='+windowref+'hideCalendar(\''+divname+'\'); type="button" value="关闭"><BR>';
   result += ' </TD>';
   result += '</TR>';
   result += '</TABLE>';
   result += '</CENTER>';
   result += '</TD></TR>';
   result += '</TABLE>';
   //result += '</FORM>';
   if (divname == "")
   {
      result += "</BODY></HTML>";
   }

   if (divname != "")
   {
      if (use_css)
      {
         document.all[divname].innerHTML = result;
      }
      if (use_layers)
      {
         var thedoc = document.layers[divname].document;
         thedoc.open;
         thedoc.write(result);
         thedoc.close();
      }
   }
   else
   {
      CALWINDOW.document.open();
      CALWINDOW.document.write(result);
      CALWINDOW.document.close();
   }
}

//使用自定义函数来接受日历返回的日期
function showBeginDate( year, month, date )
{

   var a = new Array('', '1', '2', '3', '4', '5', '6', '7', '8', '9', '9', '11', '12');
   month = a[month];
   document.getElementById("date1").value = "" + year + "-" + month +"-"+ date;
   hideCalendar('calendar');
}
function showEndDate( year, month, date )
{

   var a = new Array('', '1', '2', '3', '4', '5', '6', '7', '8', '9', '9', '11', '12');
   month = a[month];
   document.getElementById("date2").value = "" + year + "-" + month +"-"+ date;
   hideCalendar('calendar');
}
//调用示例
//<script type="text/javascript" language="javascript" src="http://www.panjk.com/js/Calendar.js"></script>
//自<input name="date1" id="date1" runat="server" style="width: 87px" />
//<a href="javascript:showCalendar('calendar','date1','showBeginDate')">
//选择</a>&nbsp;&nbsp;&nbsp;至<input name="date2" id="date2" runat="server" style="width: 87px" />
//<a href="javascript:showCalendar('calendar','date2','showEndDate')">选择</a>