Dynamic Calendar II IE4+ NS6+.

Hoạt động tốt với trình duyệt IE4+, NS6+

1. đặt trong HEAD

<script language="JavaScript">
var ns6=document.getElementById&&!document.all
var ie4=document.all
var Selected_Month;
var Selected_Year;
var Current_Date = new Date();
var Current_Month = Current_Date.getMonth();
var Days_in_Month = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
var Month_Label = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December');
var Current_Year = Current_Date.getYear();
if (Current_Year < 1000)
Current_Year+=1900

var Today = Current_Date.getDate();
function Header(Year, Month) {
   if (Month == 1) {
   Days_in_Month[1] = ((Year % 400 == 0) || ((Year % 4 == 0) && (Year % 100 !=0))) ? 29 : 28;
   }
   var Header_String = Month_Label[Month] + ' ' + Year;
   return Header_String;
}
function Make_Calendar(Year, Month) {
   var First_Date = new Date(Year, Month, 1);
   var Heading = Header(Year, Month);
   var First_Day = First_Date.getDay() + 1;
   if (((Days_in_Month[Month] == 31) && (First_Day >= 6)) ||
       ((Days_in_Month[Month] == 30) && (First_Day == 7))) {
      var Rows = 6;
   }
   else if ((Days_in_Month[Month] == 28) && (First_Day == 1)) {
      var Rows = 4;
   }
   else {
      var Rows = 5;
   }
   var HTML_String = '<table><tr><td valign="top"><table BORDER=4 CELLSPACING=1 cellpadding=2 FRAME="box" BGCOLOR="C0C0C0" BORDERCOLORLIGHT="808080">';
   HTML_String += '<tr><th colspan=7 BGCOLOR="FFFFFF" BORDERCOLOR="000000">' + Heading + '</font></th></tr>';
   HTML_String += '<tr><th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Sun</th><th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Mon</th><th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Tue</th><th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Wed</th>';
   HTML_String += '<th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Thu</th><th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Fri</th><th ALIGN="CENTER" BGCOLOR="FFFFFF" BORDERCOLOR="000000">Sat</th></tr>';
   var Day_Counter = 1;
   var Loop_Counter = 1;
   for (var j = 1; j <= Rows; j++) {
      HTML_String += '<tr ALIGN="left" VALIGN="top">';
      for (var i = 1; i < 8; i++) {
         if ((Loop_Counter >= First_Day) && (Day_Counter <= Days_in_Month[Month])) {
            if ((Day_Counter == Today) && (Year == Current_Year) && (Month == Current_Month)) {
               HTML_String += '<td BGCOLOR="FFFFFF" BORDERCOLOR="000000"><strong><font color="red">' + Day_Counter + '</font></strong></td>';
            }
            else {
               HTML_String += '<td BGCOLOR="FFFFFF" BORDERCOLOR="000000">' + Day_Counter + '</td>';
            }
            Day_Counter++;  
         }
         else {
            HTML_String += '<td BORDERCOLOR="C0C0C0"> </td>';
         }
         Loop_Counter++;
      }
      HTML_String += '</tr>';
   }
   HTML_String += '</table></td></tr></table>';
   cross_el=ns6? document.getElementById("Calendar") : document.all.Calendar
   cross_el.innerHTML = HTML_String;
}

function Check_Nums() {
   if ((event.keyCode < 48) || (event.keyCode > 57)) {
      return false;
   }
}
function On_Year() {
   var Year = document.when.year.value;
   if (Year.length == 4) {
      Selected_Month = document.when.month.selectedIndex;
      Selected_Year = Year;
      Make_Calendar(Selected_Year, Selected_Month);
   }
}
function On_Month() {
   var Year = document.when.year.value;
   if (Year.length == 4) {
      Selected_Month = document.when.month.selectedIndex;
      Selected_Year = Year;
      Make_Calendar(Selected_Year, Selected_Month);
   }
   else {
      alert('Please enter a valid year.');
      document.when.year.focus();
   }
}

function Defaults() {
   if (!ie4&&!ns6)
   return
   var Mid_Screen = Math.round(document.body.clientWidth / 2);
   document.when.month.selectedIndex = Current_Month;
   document.when.year.value = Current_Year;
   Selected_Month = Current_Month;
   Selected_Year = Current_Year;
   Make_Calendar(Current_Year, Current_Month);
}

function Skip(Direction) {
   if (Direction == '+') {
      if (Selected_Month == 11) {
         Selected_Month = 0;
         Selected_Year++;
      }
      else {
         Selected_Month++;
      }
   }
   else {
      if (Selected_Month == 0) {
         Selected_Month = 11;
         Selected_Year--;
      }
      else {
         Selected_Month--;
      }
   }
   Make_Calendar(Selected_Year, Selected_Month);
   document.when.month.selectedIndex = Selected_Month;
   document.when.year.value = Selected_Year;
}
</script>

2. đặt trong  BODY

<div id=NavBar style="position:relative;width:286px;top:5px;" align="left">
<form name="when"><table>
<tr>
   <td><input type="button" value="<-- Last" onClick="Skip('-')"></td>
   <td> </td>
   <td><select name="month" onChange="On_Month()">
<script language="JavaScript1.2">
if (ie4||ns6){
   for (j=0;j<Month_Label.length;j++) {
      document.writeln('<option value=' + j + '>' + Month_Label[j]);
   }
}
</script>
       </select>
   </td>
   <td><input type="text" name="year" size=4 maxlength=4 onKeyPress="return Check_Nums()" onKeyUp="On_Year()"></td>
   <td> </td>
   <td><input type="button" value="Next -->" onClick="Skip('+')"></td>
</tr></table></form></div>
<div id=Calendar style="position:relative;width:238px;top:-2px;" align="left"></div>

3. Thêm thuộc tính onLoad="Defaults()" vào thẻ <body> để nó như thế này:

<body onLoad="Defaults()">

Thanks: Author: Jason Moon  & dynamicdrive