function checkdates ( form )  {
// get variables for the destinations and months of travel
var origin=document.forms[0].ORIGIN.selectedIndex;
fromairport=document.forms[0].ORIGIN.options[origin].value;
var dest=document.forms[0].DESTINATION.selectedIndex;
toairport=document.forms[0].DESTINATION.options[dest].value;
var month=document.forms[0].MONTHYEAR.selectedIndex;
godate=document.forms[0].MONTHYEAR.options[month].value;
var rmonth=document.forms[0].RMONTHYEAR.selectedIndex;
backdate=document.forms[0].RMONTHYEAR.options[rmonth].value;


// are they going from or to chambery?
if (fromairport!="CMF" && toairport!="CMF")
{
	// They aren't going to CMF, so are they travelling on a forbidden date?
	if (godate=="NOV2008" || backdate=="NOV2008"|| godate=="DEC2008" || backdate=="DEC2008"||godate=="JAN2009" || backdate=="JAN2009"|| godate=="FEB2009" || backdate=="FEB2009" || godate=="MAR2009" || backdate=="MAR2009"|| godate=="APR2009" || backdate=="APR2009")
	   {
	alert('Sorry, but the schedule on this route for travel after October 2008 is not yet available for sale');
        return false;
	   }
}
return true;
			}