Set Lost Focus and cusrosr go same control

    Method 1 
    setFocus(txts_StockNo);
  //set focus
        public static void setFocus(UIElement element)
        {
            if (!element.Focus())
            {
                element.Dispatcher.BeginInvoke(DispatcherPriority.Input, new ThreadStart(delegate()
                {
                    element.Focus();
                }));
            }
            else
            {
                element.Dispatcher.BeginInvoke(DispatcherPriority.Input, new ThreadStart(delegate()
                    {
                        element.Focus();
                    }));
            }
        }
    Method 2

    Write Down code on lost focus instead of PreviewLostKeyboardFocus_1

  private void txtPhone_PreviewLostKeyboardFocus_1(object sender, KeyboardFocusChangedEventArgs e)
        {
            if (txtPhone.Value.ToString().Length < 10 && txtPhone.Value.ToString().Length != 0)
            {
                MessageBox.Show("Enter 10 digit home number", "DMS", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                //txtPhone.Focus();
                e.Handled = true;
            }
            else
            {
                if (Convert.ToString(txtPhone.Value) != "")
                {


                 //// wrote down ur code


                }
            }