function setAirSelectValue(name, parentValue, selectedValue) {
  if(parentValue != "") {
    changeSelect(name, parentValue);
    setSelectSelected(name, selectedValue);
  }
}

function setAirSelectSelected(name, selectedValue) {
  var options = document.air_form[name].options;
  for(var i = 0; i < options.length; i++) {
    if(options[i].value == selectedValue) {
    options[i].selected = true;
    }
  }
}
function changeAirSelect(name, parentValue) {
  var select = document.getElementById(name + "Air");
  if (!select) return;
  var options = getAirOptions(name, parentValue);
  select.options.length=1;
  for(var i = 0; i < options.length; i++) {
    select.options.add(options[i]);
  }
}