var airportSrc = new Object();
var airportDest = new Object();

function selectAirport(field, city) {
  var cities = airportSrc[city];
  if(typeof (cities) != 'undefined') {
	  field.length = cities.length;
	  for (var i = 0; i < cities.length; i++) {
	    var city_arr = cities[i].split("|");
	    field[i].value = city_arr[0];
		field[i].text = city_arr[1];
	  }
	  field.selectedIndex = 0;
  } else {
  	field.length = 0;
  }
}