<HTML>
<HEAD>
<SCRIPT LANGUAGE="JavaScript">
<!--
function setToday() {
var now   = new Date();
var day   = now.getDate();
var month = now.getMonth();
var year  = now.getYear();
this.focusDay = day;
document.calControl.month.selectedIndex = month;
document.calControl.year.value = year;
displayCalendar(month, year);
}
function isFourDigitYear(year) {
if (year.length != 4) {
alert ("Год может состоять только из 4 цифр.");
document.calControl.year.select();
document.calControl.year.focus();
} else { return true; }
}
function selectDate() {
var year  = document.calControl.year.value;
if (isFourDigitYear(year)) {
var day   = 0;
var month = document.calControl.month.selectedIndex;
displayCalendar(month, year);
    }
}

function setPreviousYear() {
var year  = document.calControl.year.value;
if (isFourDigitYear(year)) {
var day   = 0;
var month = document.calControl.month.selectedIndex;
year--;
document.calControl.year.value = year;
displayCalendar(month, year);
   }
}
function setPreviousMonth() {
var year  = document.calControl.year.value;
if (isFourDigitYear(year)) {
var day   = 0;
var month = document.calControl.month.selectedIndex;
if (month == 0) {
month = 11;
if (year > 1000) {
year--;
document.calControl.year.value = year;
}
} else { month--; }
document.calControl.month.selectedIndex = month;
displayCalendar(month, year);
   }
}
function setNextMonth() {
var year  = document.calControl.year.value;
if (isFourDigitYear(year)) {
var day   = 0;
var month = document.calControl.month.selectedIndex;
if (month == 11) {
month = 0;
year++;
document.calControl.year.value = year;
} else { month++; }
document.calControl.month.selectedIndex = month;
displayCalendar(month, year);
   }
}
function setNextYear() {
var year = document.calControl.year.value;
if (isFourDigitYear(year)) {
var day = 0;
var month = document.calControl.month.selectedIndex;
year++;
document.calControl.year.value = year;
displayCalendar(month, year);
   }
}
function displayCalendar(month, year) {       
month = parseInt(month);
year = parseInt(year);
var i = 0;
var days = getDaysInMonth(month+1,year);
var firstOfMonth = new Date (year, month, 1);
var startingPos = firstOfMonth.getDay();
days += startingPos;
document.calButtons.calPage.value  =   " Вс Пн Вт Ср Чт Пт Сб";
document.calButtons.calPage.value += "\n --------------------";
for (i = 0; i < startingPos; i++) {
if ( i%7 == 0 ) document.calButtons.calPage.value += "\n ";
document.calButtons.calPage.value += "   ";
}
for (i = startingPos; i < days; i++) {
if ( i%7 == 0 ) document.calButtons.calPage.value += "\n ";
if (i-startingPos+1 < 10)
document.calButtons.calPage.value += "0";
document.calButtons.calPage.value += i-startingPos+1;
document.calButtons.calPage.value += " ";
}
for (i=days; i<42; i++)  {
if ( i%7 == 0 ) document.calButtons.calPage.value += "\n ";
document.calButtons.calPage.value += "   ";
}
document.calControl.Go.focus();
}
function getDaysInMonth(month,year)  {
var days;
if (month==1 || month==3 || month==5 || month==7 || month==8 || month==10 || month==12)  days=31;
else if (month==4 || month==6 || month==9 || month==11) days=30;
else if (month==2)  {
if (isLeapYear(year)) { days=29; }
else { days=28; }
}
return (days);
}
function isLeapYear (Year) {
if (((Year % 4)==0) && ((Year % 100)!=0) || ((Year % 400)==0)) {
return (true);
} else { return (false); }
}
// -->
</SCRIPT>
<BODY onLoad="setToday()">
<CENTER>
<FORM NAME="calControl" onSubmit="return false;">
<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0>
<TR><TD COLSPAN=7>
<CENTER>
<SELECT NAME="month" onChange="selectDate()">
<OPTION>Январь
<OPTION>Февраль
<OPTION>Март
<OPTION>Апрель
<OPTION>Май
<OPTION>Июнь
<OPTION>Июль
<OPTION>Август
<OPTION>Сентябрь
<OPTION>Октябрь
<OPTION>Ноябрь
<OPTION>Декабрь
</SELECT>
<INPUT NAME="year" TYPE=TEXT SIZE=4 MAXLENGTH=4>
<INPUT TYPE="button" NAME="Go" value="Считать" onClick="selectDate()">
</CENTER>
</TD>
</TR>
</FORM>
<FORM NAME="calButtons">
<TR><TD align="center"><textarea FONT="Courier" NAME="calPage" WRAP=no ROWS=8 COLS=22></textarea></TD><TR><TD><CENTER>
<INPUT TYPE=BUTTON NAME="previousYear" VALUE=" <<  "    onClick="setPreviousYear()">
<INPUT TYPE=BUTTON NAME="previousYear" VALUE="  <  "    onClick="setPreviousMonth()">
<INPUT TYPE=BUTTON NAME="previousYear" VALUE="Сегодня"    onClick="setToday()">
<INPUT TYPE=BUTTON NAME="previousYear" VALUE="  >  "    onClick="setNextMonth()">
<INPUT TYPE=BUTTON NAME="previousYear" VALUE="  >> "    onClick="setNextYear()">
</CENTER></TD></TR>
</TABLE></FORM></FONT>
</body>
</html>