in Figure 5.29. Figure 5.29. The tag library mode allows you to customize the technologies that the tab library can be used in. [View full size image]   Aside from the same Tags option mentioned previously, the following two editing options are exposed in tag library editing mode: Used in: Check the technologies in which you want your tag library to be available. Tag prefix: Technologies such as ASP.NET and JSP rely on precompiled controls written with tag prefixes. As a rule of thumb, the ASP.NET tag prefix is asp: while the JSP tag prefix is jsp:. As you will see later in the book, a text box is represented in ASP.NET as <asp:textbox> where asp: is the tag prefix and textbox is the tag name. This tells the ASP.NET runtime to render a text box, available from the ASP web control library. If your custom tag library is based on a tag prefix, enter that prefix here. Finally, you can see the features exposed by the attribute editing mode by expanding a specific tag from the tree. To demonstrate this, I'll expand the <a> tag. Doing so displays a list of attributes supported by the <a> tag (see Figure 5.30). Figure 5.30. Expand a tag from the tree to see all the attributes supported by the tag. [View full size image]   Most of the features in this interface are similar to the previous two. The one difference is the Attribute type and Values options. These features are highlighted with more detail below: Attribute type: Choose one of ten options from this menu to assign a specific type to the selected or custom made attribute. For instance, choosing the Color option exposes the color picker when the attribute is added; choosing Font displays a list of selectable web-based fonts. Values: Selecting the Enumerated option from the Attribute Type menu enables this text box which allows you to enter comma-separated values. With the target attribute selected and the Enumerated attribute type option chosen, the four targets discussed in Chapter 3 become available. NOTE The four targets are _top, _blank, _self, and _parent.   Again, you probably won't find yourself making too many changes, if any, to the HTML tag library. In reality, the Tag Library Editor dialog makes the most sense when you're working with your own custom tags. To create your own tag library complete with tags, attributes, and values, follow these steps: 1. Start by minimizing any open tag libraries so that you can see your new tag library at the bottom of the list. Click the Add (+) button and select the New Tag Library option from menu. 2. When the New Tag Library dialog appears, enter a unique name and click OK. I'll enter Vehicle Tags. The new tag library is added to the bottom of the list. 3. Let's add a tag to the library. With the Vehicle Tags library selected, I'll choose the New Tags option from the Add (+) menu. The New Tags dialog appears. 4. In the dialog, make sure that the Vehicle Tags option is selected from the Tag library menu. Now enter a new tag name in the Tag Names text box. I'll enter car. Ensure that the Have Matching End Tags check box is checked. This guarantees that after you've added the closing > symbol in Code view, the end tag is automatically added. Click OK.