disable add permission if necessary

src/lupermissionsedit.js

 
                     $scope.permissions = [];
                     $scope.allPermissions = [];
+                    $scope.allPermissionsCleared = [];
                     $scope.tmpPermission = {
                         Name: "",
                         Value: true
                         luModel.getGetAllPromise(null, null, promiseLoadPermissions)
                             .then(function (permissions) {
                                 $scope.permissions = permissions.Data;
+                                $scope.allPermissionsCleared = [];
+                                for (var i = 0; i < $scope.allPermissions.length; ++i) {
+                                    var p = $scope.allPermissions[i];
+                                    if ($scope.permissions.find(function(p2)
+                                        {
+                                            return p.Name == p2.Name;
+                                        }) == null) {
+                                        $scope.allPermissionsCleared.push(p);
+                                    }
+                                }
+                                if ($scope.allPermissionsCleared.length > 0) {
+                                    $scope.tmpPermission.Name = $scope.allPermissionsCleared[0].Name;
+                                }
+                                else {
+                                    $scope.tmpPermission.Name = "";
+                                }
                             }, luticateDialogErrorHelper.errorDialog);
                     };
 
                         luticateAuthPermissions.getAll(null, promiseLoadAllPermissions)
                             .then(function (permissions) {
                                 $scope.allPermissions = permissions.Data;
-                                $scope.tmpPermission.Name = $scope.allPermissions[0].Name;
+                                $scope.loadPermissions();
                             }, luticateDialogErrorHelper.errorDialog);
                     };
 
-                    $scope.loadPermissions();
                     $scope.loadAllPermissions();
                 }
             };
 '    {{ tmpPermission.Name }} <span class="caret"></span>' +
 '    </a>' +
 '    <ul class="dropdown-menu">' +
-'    <li ng-repeat="permission in allPermissions">' +
+'    <li ng-repeat="permission in allPermissionsCleared">' +
 '    <a href="" ng-click="tmpPermission.Name = permission.Name">{{ permission.Name}}</a>' +
 '</li>' +
 '</ul>' +
 '<li><a href="" ng-click="tmpPermission.Value = true">Allow</a></li>' +
 '</ul>' +
 '</div>' +
-'<button type="button" class="btn btn-default" ng-click="addPermission(tmpPermission)">' +
+'<button type="button" class="btn btn-default" ng-click="addPermission(tmpPermission)" ng-disabled="allPermissionsCleared.length == 0">' +
 '    <span class="glyphicon glyphicon-plus" aria-hidden="true"></span> Add' +
 '    </button>' +
 '    </div>' +