ng-model Form $scope.txthn= data; ไม่แสงผลออกมา Textbox

<input type="text" name="hn" id="hn" ng-model="txthn" class="form-control">
<script>
var app = angular.module('live_search_app', []);
app.controller('live_search_controller', function($scope, $http){
 $scope.fetchData = function(){
  $http({
   method:"POST",
   url:"fetch.php",
   data:{search_query:$scope.search_query}
  }).success(function(data){
   $scope.searchData = data;
   $scope.txthn= data;

  });
 };
});
</script>