diff --git a/backend/app/people/inquisitor-validator.js b/backend/app/people/inquisitor-validator.js
index d6fcf64399f193e398e7c018af582904af50c72b..0a9937c97d05c04247f8047f66a11cc4d3477d19 100644
--- a/backend/app/people/inquisitor-validator.js
+++ b/backend/app/people/inquisitor-validator.js
@@ -6,7 +6,7 @@ var areBadPetsHere = function (pets) {
     return false
   }
   var m = pets.map(function (pet) {
-    return pet == ''
+    return pet == '' || pet == undefined
   })
   return m.reduce(function (i,j) {
     return i || j
@@ -14,6 +14,7 @@ var areBadPetsHere = function (pets) {
 }
 
 var inquisitor = function (next) {
+  console.log(this)
   if(this.name == ''){
     next(erroneous_name)
   }
diff --git a/backend/app/people/people.js b/backend/app/people/people.js
index 1aefc2c12fdf10c9580520dc77236ae90ef8fcb8..4c918eac35fd1f6f0a7832104be0e887f621f57d 100644
--- a/backend/app/people/people.js
+++ b/backend/app/people/people.js
@@ -54,10 +54,10 @@ db.once('open',function () {
   }
 
   people.modifyPet = function (id, old_pet_name, new_pet_name, callback) {
-    people.removePet(id,old_pet_name,function () {
-      people.addPet(id,new_pet_name,function () {
-        callback()
-      })
+    people.model.findById(id).then(function (person) {
+      person.pets.splice(person.pets.indexOf(old_pet_name),1)
+      person.pets.push(new_pet_name)
+      person.save(callback)
     })
   }
 
diff --git a/frontend/app/core/people.js b/frontend/app/core/people.js
index d1702565bea31607b1a9c0337e1b4019ecdf40fe..319fc18b8df410af2a16f8088e58381a46cfa7c5 100644
--- a/frontend/app/core/people.js
+++ b/frontend/app/core/people.js
@@ -8,6 +8,12 @@ app.controller('peopleCtrl',function ($scope,ngDialog,people) {
     })
   }
 
+  $scope.badData = function () {
+    ngDialog.open({
+      template:'../error-partial.html'
+    })
+  }
+
   this.load()
 
   $scope.remove = function (item) {
@@ -16,7 +22,7 @@ app.controller('peopleCtrl',function ($scope,ngDialog,people) {
 
   $scope.add = function () {
     console.log("adding")
-    people.add($scope.name,self.load)
+    people.add($scope.name,self.load,$scope.badData)
     $scope.name = ''
   }
 
@@ -34,7 +40,7 @@ app.controller('peopleCtrl',function ($scope,ngDialog,people) {
     people.addPet(person, pet, function () {
       self.load()
       $scope.pet = ''
-    })
+    }, $scope.badData)
   }
 
   $scope.do = function (person,pet) {
diff --git a/frontend/app/core/peopleService.js b/frontend/app/core/peopleService.js
index 5447619f73c1306cfa31340bdb918e9b9538c276..fbb582a7fec0295ae3b96975eb4bc4aaed421aa0 100644
--- a/frontend/app/core/peopleService.js
+++ b/frontend/app/core/peopleService.js
@@ -7,18 +7,18 @@ app.service('people', function ($http) {
     $http.delete('http://127.0.0.1:8000/people/'+item._id).then(callback)
   }
 
-  this.add = function (n,callback) {
-    $http.post('http://127.0.0.1:8000/people',{name:n}).then(callback)
+  this.add = function (n,callback,reject) {
+    $http.post('http://127.0.0.1:8000/people',{name:n}).then(callback).catch(reject)
   }
 
-  this.modify = function (item,callback) {
+  this.modify = function (item,callback,reject) {
     $http.put('http://127.0.0.1:8000/people',{person_id: item._id, name: item.name})
-    .then(callback)
+    .then(callback).catch(reject)
   }
 
-  this.addPet = function (item,pet_name,callback) {
+  this.addPet = function (item,pet_name,callback,reject) {
     $http.post('http://127.0.0.1:8000/people/pets',{person_id: item._id, petname: pet_name})
-    .then(callback)
+    .then(callback).catch(reject)
   }
 
   this.removePet = function (item, pet_name, callback) {
@@ -26,12 +26,12 @@ app.service('people', function ($http) {
     .then(callback)
   }
 
-  this.modifyPet = function (item,old_pet_name,new_petname,callback) {
+  this.modifyPet = function (item,old_pet_name,new_petname,callback,reject) {
     $http.put('http://127.0.0.1:8000/people/pets',
     {
       person_id: item._id,
       old_petname: old_pet_name,
       new_petname: new_petname
-    }).then(callback)
+    }).then(callback).catch(reject)
   }
 })
diff --git a/frontend/app/error-partial.html b/frontend/app/error-partial.html
new file mode 100644
index 0000000000000000000000000000000000000000..7194fcbf0eb150241c50acdcc711430a926588e1
--- /dev/null
+++ b/frontend/app/error-partial.html
@@ -0,0 +1,9 @@
+<div>
+  <h1>Error</h1>
+    Erroneous data.
+  <div class="row">
+    <div class="6u align-center">
+      <button ng-click='closeThisDialog()' >Oops</button>
+    </div>
+  </div>
+</div>