javascript - Delete Data from Firebase server Using key or index method -

i need delete entry firebase using angularjs.the problem if use index deletes entries firebase, , if use key method nothing. here code controller.it supposed take key firebase 1 of partials.

$scope.deletecontact = function(key){               contactlist.destroy(key);               deletealert.show();                         };  contactfactory.factory('contactlist',   function($firebaseobject,$firebasearray){  var contact = new firebase("https://mycontactmanager.firebaseio.com/"); 

this function delete entry firebase

destroy: function(key){ contact.remove(key);                       } 

here code partial

        <td>{{contactitem.name}}</td>         <td>{{contactitem.email}}</td>         <td>{{contactitem.phone}}</td>         <td><a href="#/contact/{{key}}" class="btn btn-success btn-xs">view contact</a>         <button class="btn btn-danger btn-xs col-sm-offset-1" ng-click="deletecontact(key)\">delete</button>         </td>       </tr>        </tbody>          

since ref root of firebase database, need find 1 child , remove child below

ref.child(key).$remove().then(function() {     // code after remove }); 

refer more here https://www.firebase.com/docs/web/libraries/angular/api.html#angularfire-firebaseobject-remove