function CheckArrivalAirport(sender, args)
    {
        if(document.getElementById(airportDropDown).options.selectedIndex == 0)
        args.IsValid= false;
        else
        args.IsValid= true;
    }
    function CheckCountOfHotelLocation(sender, args)
    {
    if(document.getElementById(hotelLocationDropDown).options.count <= 0)
    args.IsValid= false;
    else
    args.IsValid= true;
    }
    function CheckHotelLocation(sender, args)
    {
    if(document.getElementById(hotelLocationDropDown).options.selectedIndex == 0)
    args.IsValid= false;
    else
    args.IsValid= true;
    }