function CheckCalendarDates(form){
	var monthDays = DaysInMonth(form.Month.options[form.Month.selectedIndex].value, form.Year.options[form.Year.selectedIndex].value);		

	if (form.Day.options[form.Day.selectedIndex].value > monthDays){
		form.Day.selectedIndex = monthDays - 1;
	}	
}

function UpdateCalendarDates(form, updateType){
	nowDate = new Date();
  currentDate = new Date(form.Year.options[form.Year.selectedIndex].value, form.Month.selectedIndex, form.Day.selectedIndex + 1);
  switch (updateType) {
  	case 1:
  		// add a week using date functions
  		newDate = new Date(currentDate)
			newDate = new Date(newDate.setDate(newDate.getDate() + 7));
			form.Month.selectedIndex = newDate.getMonth();
			form.Day.selectedIndex = newDate.getDate() - 1;
			form.Year.selectedIndex = newDate.getYear() - nowDate.getYear() + YearFromSelectOffset;
			CheckCalendarDates(form);
			form.submit();
  		break;
  	case 2:
  		// remove a week using date functions
  		newDate = new Date(currentDate)
			newDate = new Date(newDate.setDate(newDate.getDate() - 7));
			form.Month.selectedIndex = newDate.getMonth();
			form.Day.selectedIndex = newDate.getDate() - 1;
			form.Year.selectedIndex = newDate.getYear() - nowDate.getYear() + YearFromSelectOffset;
			CheckCalendarDates(form);
			form.submit();
  		break;
  	case 3: 
  		// add a month to the form
  		if  (form.Month.selectedIndex == 11){
  			form.Year.selectedIndex = form.Year.selectedIndex + 1;
  			form.Month.selectedIndex = 0;
  		}
  		else{
  			form.Month.selectedIndex = form.Month.selectedIndex + 1;
  		}
			CheckCalendarDates(form);
			form.submit();
  		break;
  	case 4:
  		// remove a month from the form
  		if  (form.Month.selectedIndex == 0){
  			form.Year.selectedIndex = form.Year.selectedIndex - 1;
  			form.Month.selectedIndex = 11;
  		}
  		else{
  			form.Month.selectedIndex = form.Month.selectedIndex - 1;
  		}
			CheckCalendarDates(form);
			form.submit();
  		break;
		default	:
			break;
  }
}

function ShowWeekView(form) {
	form.View.value = "1";
	form.submit();
}

function ShowMonthView(form) {
	form.View.value = "2";
	form.submit();
}