private void addUserToGroupButton_Click(object sender, RoutedEventArgs e)
        {
            List <string> usernamesToAdd = new List <string>();

            foreach (UserChecker uc in usersStackPanel.Children)
            {
                if ((bool)uc.checkBox.IsChecked)
                {
                    usernamesToAdd.Add(uc.nameLabel.Content.ToString());
                }
            }

            foreach (Group g in ((MainUserWindow)this.Owner).clientProxy.ReadGroups())
            {
                if (g.Owner == ((MainUserWindow)this.Owner).loggedUser.Username && g.GroupName == ((Info)((MainUserWindow)this.Owner).ContentArea.Content).nameLabel.Content.ToString())
                {
                    foreach (string usersInGroup in ((MainUserWindow)this.Owner).clientProxy.ReadFromGroup(g.GroupName))
                    {
                        ((MainUserWindow)this.Owner).clientProxy.DeleteUsersFromGroup(g.GroupName, g.Owner, usersInGroup);
                    }

                    foreach (string s in usernamesToAdd)
                    {
                        ((MainUserWindow)this.Owner).clientProxy.AddUsersToGroup(g.GroupName, g.Owner, s);
                        Audit.AddedUserToGroup(g.Owner, s, g.GroupName);
                    }

                    ((Info)((MainUserWindow)this.Owner).ContentArea.Content).listBox.ItemsSource = usernamesToAdd;
                    this.Close();
                }
            }
        }