private void Execute(object parameter)
        {
            Object[] parameters = parameter as Object[];

            String username = parameters[0] as String;
            String password = parameters[1] as String;

            CurrentUserControl = parameters[2] as UserControl;

            try
            {
                Account account = LoginProxy.ConnectToLoginService().Login(username, password);
                if (account == null)
                {
                    MessageBox.Show("Username or password is incorrect.");
                }
                else
                {
                    MessageBox.Show("Successfull login!");

                    CurrentUserControl.Content = new HomeViewModel(account);
                    CurrentUserControl.VerticalContentAlignment   = VerticalAlignment.Top;
                    CurrentUserControl.HorizontalContentAlignment = HorizontalAlignment.Left;
                    CurrentUserControl.Width  = 1500;
                    CurrentUserControl.Height = 1000;
                }
            }
            catch (Exception e)
            {
                MessageBox.Show($"Problem with connection. Message: {e.Message}");
            }
        }