private void button1_Click(object sender, RoutedEventArgs e)
        {
            if (treeView1.SelectedItem == itemTree)
            {
                return;
            }
            var exten = dataClass.GetExtenFromName(treeView1.SelectedItem.ToString());

            _sipekInstance.CallManager.createOutboundCall("*222" + exten.Trim());
            button4.Content = "Hangup";
            //this.Visibility = System.Windows.Visibility.Hidden;
        }
        void item_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            var newItem = sender as TreeViewItem;

            if (treeView1.SelectedItem == item)
            {
                return;
            }
            else
            {
                exten = dataClass.GetExtenFromName(treeView1.SelectedItem.ToString());
            }
            if (XferNow != null)
            {
                XferNow(this, e);
            }
        }