function changeDaysInMonth(monthSelect)
{
        daysInMonth = 31;
        monthIndex = monthSelect.selectedIndex;
        monthName = monthSelect.options[monthIndex].value;
        if (monthName == "february")
        {
                daysInMonth = 28;
        }
	else
	{
		if (
		monthName == "september"
		||
		monthName == "april"
		||
		monthName == "june"
		||
		monthName == "november"

		)
		{
			daysInMonth = 30;
		}
	}
        monthSelect.form.day.options.length = daysInMonth+1;
	monthSelect.form.day.options[0] = new Option("Select day:", "null");
        for (day=1;day<=daysInMonth;day++)
        {
                monthSelect.form.day.options[day] = new Option(day, day);
        }
}