They open the catalog and select the missing item

Modifying the Content with an EditorZone

ID="AppearanceEditorPart1" />

<asp:LayoutEditorPart Runat="server" ID="LayoutEditorPart1" />

To make this display appear, the user first chooses Edit from the Change the Layout menu. This selection displays the various controls, as shown in Figure 6.17, and makes the Edit selection for each control accessible. Choosing the Edit option for a particular control displays both the Appearance EditorPart and LayoutEditorPart controls. Notice that the AppearanceEditorPart control lets the user change the title for the display element, as well as its width and height. The user can also choose to display the element with a title and border, or without either item. The user can even hide unwanted items from view. The LayoutEditorPart control makes it possible to move Web page ele-ments around and change their state from normal (viewable) to minimized (just the title showing). The Zone Index field changes the control’s position within a particular zone.

<ZoneTemplate>

<asp:PageCatalogPart ID="PageCatalogPart1" Runat="server" />

It’s interesting to note that even though you don’t write any script to use WebParts, the IDE adds these scripts for you automatically. Right-click the example Web page and choose View Source from the context menu. You’ll see the source code for the example Web page as the browser sees it. The first thing you’ll notice is that the page contains many scripts sprinkled throughout the page, as shown in Figure 6.19.

Viewing the source for this Web page points out an important reason for learning the scripting lan-guage that you choose for Visual Web Developer. Even if you decide not to use scripting for your page, there’s a good chance that anything you ask the IDE to perform automatically will produce some client-side code. Knowing how this code works can help you diagnose problems with the Web