function validateIslandTravelForm(form) 
{
   if (form.FrAirport.value != "" && 
       form.FromDate.value != "" && 
       form.ToAirport.value != "" && 
       form.ToDate.value != "" ) {
      return true;
   }
   else {
      alert("All fields are required.");
      return false;
   }
}