function UpdateList(object) {
  // Remove all existing items from Airport list
  object.Airport.options.length = 0;

  var defaultSelected = false;
  var selected = false;

  // add items based on the selected option of Travel
  if (object.Travel.options[0].selected) {
    var optionName = new Option("Barcelona", "Barcelona", defaultSelected, selected);
    var length = object.Airport.length;
    object.Airport.options[length] = optionName;
  }

  if (object.Travel.options[1].selected) {
    var optionName = new Option("Barcelona", "Girona", defaultSelected, selected);
    var length = object.Airport.length;
    object.Airport.options[length] = optionName;

    var optionName = new Option("Girona", "ItemTwoValue", defaultSelected, selected);
    var length = object.Airport.length;
    object.Airport.options[length] = optionName;
    
    var optionName = new Option("Reus", "ItemTwoValue", defaultSelected, selected);
    var length = object.Airport.length;
    object.Airport.options[length] = optionName;
  }

  if (object.Travel.options[2].selected) {
    var optionName = new Option("Not Valid", "FirstItemValue", defaultSelected, selected);
    var length = object.Airport.length;
    object.Airport.options[length] = optionName;
  }
  
    if (object.Travel.options[3].selected) {
    var optionName = new Option("Not Valid", "FirstItemValue", defaultSelected, selected);
    var length = object.Airport.length;
    object.Airport.options[length] = optionName;
  }
  
  // Do the next line to make sure the top item is selected
  object.Airport.options[0].selected = true;
}