/// <summary>
 /// Add new model.
 /// </summary>
 private void AddModel(GXDeviceManufacturer man)
 {            
     GXDeviceModel model = new GXDeviceModel();
     model.Status = DownloadStates.Add;
     GXDeviceModelForm dlg = new GXDeviceModelForm(model);
     if (dlg.ShowDialog() == DialogResult.OK)
     {
         man.Models.Add(model);
         //Add tree item.
         TreeNode parentNode = ItemToTreeNode[man] as TreeNode;
         TreeNode node = parentNode.Nodes.Add(model.Name);
         node.Tag = model;
         ItemToTreeNode[model] = node;
         //Add list item.
         ListViewItem li = PresetList.Items.Add(model.Name);
         li.Tag = model;
         ItemToListItem[model] = li;
         //Select new item from the tree.
         PresetTree.SelectedNode = node;
     }
 }
 /// <summary>
 /// Edit selected model.
 /// </summary>
 private void EditModel(GXDeviceModel model)
 {
     GXDeviceModelForm dlg = new GXDeviceModelForm(model);
     if (dlg.ShowDialog() == DialogResult.OK)
     {
         TreeNode node = ItemToTreeNode[model] as TreeNode;
         node.Text = model.Name;
     }
 }