/// <summary>
        /// Add auto scaling group click event handler
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnAddASG_Click(object sender, RoutedEventArgs e)
        {
            if (this.vm.IsVpc && this.vm.SelectedVpc == null)
            {
                MessageBox.Show("Currently there is no VPC selected. Please select a VPC and then try again.", "No Selected VPC", MessageBoxButton.OK, MessageBoxImage.Information);
                return;
            }

            Window win = new AsgWindow((ViewModel)this.DataContext, false);
            win.Owner = Window.GetWindow(this);
            ((AsgWindow)win).AsgAdded += new EventHandler(asgitem_added);
            win.ShowDialog();
        }
 /// <summary>
 /// Event handler for "Update Auto Scaling Group" context menu click 
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void mnuUpdateAsg(object sender, RoutedEventArgs e)
 {
     Window win = new AsgWindow((ViewModel)this.DataContext, true);
     win.Owner = Window.GetWindow(this);
     ((AsgWindow)win).AsgUpdated += new EventHandler(asgitem_updated);
     win.ShowDialog();
 }