Angular ng-model combobox with other option and a textbox

function Ctrl($scope) {
  $scope.items = ["English","French","German","Other"];
  
  $scope.personData = { language : "none" };
  

  
}

<!doctype html>
<html ng-app>
  <head>
    <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.5/angular.min.js"></script>
    <script src="script.js"></script>

  </head>
  <body>

<div ng-controller="Ctrl">
  <select ng-model="lang" ng-change="personData.language=lang" ng-options="item for item in items">
  </select>
  <br>
  
  
 <input type="text" ng-model="olang" ng-show="lang == 'Other'" ng-change="personData.language=olang" placeholder="Other Language">
  <br>
  Person Data Object
  <br>
  {{personData}}
</div>



  </body>
</html>