angularJS实现动态添加,删除div方法

<div class="accordion-inner">
  <div class="alert alert-info fade in" ng-repeat="permission in permissions">授权给:
    <select id="" class="grantees" disabled="" style=" margin-bottom: 3px;" ng-model="permission.grantee">
      <option value="everyone">所有人</option>
      <option value="authenUsers">已认证的用户</option>
      <option value="me" selected="">我自己</option>
    </select>
    <input type="checkbox" checked="" class="permissions" disabled="" ng-model="permission.port1">Open/Download
    <input type="checkbox" checked="" class="permissions" disabled="" ng-model="permission.port2">View Permissions
    <input type="checkbox" checked="" class="permissions" disabled="" ng-model="permission.port3">Edit Permissions
    <button class="btn" type="button" style="float: right;" ng-click="delPermission($index)">删除</button>
  </div>
  <div>
    <button class="btn" type="button" ng-click="addPermission($index)">增加访问许可</button>
  </div>
  <br>
  <div>
    <button class="btn btn-primary" type="button">保存</button>
    <button class="btn" type="button">取消</button>
  </div>
</div>

//增加许可访问div
$scope.permissions = [{grantee: "",port1:"",port2:"",port3:""}];
$scope.addPermission = function($index){
  $scope.permissions.splice($index + 1, 0,
    {grantee:"", port1:"",port2:"",port3:""});
}
//删除许可访问div
$scope.delPermission = function($index){
  $scope.permissions.splice($index, 1);
}