fgdata/gui/dialogs/airports.xml

<?xml version="1.0"?>

<PropertyList>
  <name>airports</name>
  <layout>vbox</layout>

  <text>
    <label>Select an Airport</label>
  </text>

  <hrule/>

  <nasal>
    <open>
      var id = "";
      var node = props.globals.getNode("/sim/gui/dialogs/airports", 1);
      if (node.getNode("list") == nil)
          node.getNode("list", 1).setValue("");

      node = node.getNode("list");

      var listbox = func {
          id = pop(split(" ", node.getValue()));
          id = substr(id, 1, size(id) - 2);  # strip parentheses
      }

      var apply = func {
          setprop("/sim/presets/airport-id", id);
          setprop("/sim/presets/longitude-deg", -9999);
          setprop("/sim/presets/latitude-deg", -9999);
          setprop("/sim/presets/altitude-ft", -9999);
          setprop("/sim/presets/airspeed-kt", 0);
          setprop("/sim/presets/offset-distance-nm", 0);
          setprop("/sim/presets/offset-azimuth-deg", 0);
          setprop("/sim/presets/glideslope-deg", 0);
          setprop("/sim/presets/heading-deg", 0);
          setprop("/sim/presets/runway", "");
      }
    </open>
  </nasal>

  <airport-list>
    <name>airport-list</name>
    <pref-width>440</pref-width>
    <pref-height>360</pref-height>
    <property>/sim/gui/dialogs/airports/list</property>
    <binding>
      <command>dialog-apply</command>
      <object-name>airport-list</object-name>
    </binding>
    <binding>
      <command>nasal</command>
      <script>listbox()</script>
    </binding>
  </airport-list>

  <group>
    <layout>hbox</layout>
    <default-padding>4</default-padding>

    <text>
      <label>Airport:</label>
      <pref-width>60</pref-width>
    </text>

    <input>
      <name>input</name>
      <pref-width>280</pref-width>
      <property>/sim/gui/dialogs/airports/list</property>
      <binding>
        <command>dialog-apply</command>
        <object-name>input</object-name>
      </binding>
      <binding>
        <command>dialog-update</command>
        <object-name>airport-list</object-name>
      </binding>
    </input>

    <button>
      <legend>Search</legend>
      <binding>
        <command>dialog-apply</command>
        <object-name>input</object-name>
      </binding>
      <binding>
        <command>dialog-update</command>
        <object-name>airport-list</object-name>
      </binding>
    </button>
  </group>

  <group>
    <layout>hbox</layout>
    <default-padding>10</default-padding>
    <empty><stretch>true</stretch></empty>

    <button>
      <legend>Apply</legend>
      <equal>true</equal>
      <default>true</default>
      <binding>
        <command>dialog-apply</command>
        <object-name>airport-list</object-name>
      </binding>
      <binding>
        <command>nasal</command>
        <script>apply()</script>
      </binding>
      <binding>
        <command>presets-commit</command>
      </binding>
    </button>

    <empty><stretch>true</stretch></empty>

    <button>
      <legend>Close</legend>
      <equal>true</equal>
      <key>Esc</key>
      <binding>
        <command>dialog-apply</command>
        <object-name>input</object-name>
      </binding>
      <binding>
        <command>dialog-close</command>
      </binding>
    </button>

    <empty><stretch>true</stretch></empty>
  </group>
</PropertyList>