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Platinum Edition Using HTML 4, XML, and Java 1.2
(Publisher: Macmillan Computer Publishing)
Author(s): Eric Ladd
ISBN: 078971759x
Publication Date: 11/01/98

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Alternative HTML

One of the great features of HTML is that it enables you to provide alternative content if your primary content is not viewable. The HTML instruction that places an image on a page, for example, also supports the display of a text-based alternative to the image for users with text-only browsers, for users who have turned off image loading on their graphical browsers, or for users who use non-visual browsers. As you read the chapters on HTML in this book, make note of the ways you can provide alternative content on your pages. Using these techniques will also help to maximize your audience.

Alternative HTML Pages

Sometimes users cannot view an entire page. One case of this is a framed page. Although most users will probably be using a browser that can process frames, you still need to be sensitive to “frames-challenged” browsers. You can do this by creating non-frames versions of your framed pages. Many sites that use frames provide links to pages that contain the same information but don’t use frames (see Figure 2.9).

Alternatives to Scripts

Scripts are like images in that a user may have a browser that does not support a scripting language, or the user may have turned off the browser’s ability to parse and execute scripts. For these reasons, you should be sure to include alternative content in the event that your scripts can’t run on a user’s browser.

Fortunately, HTML 4 makes this a fairly simple matter with the <NOSCRIPT> and </NOSCRIPT> tags. Any content you place between these tags will be rendered by a script-capable browser when it is unable to run a script. Browsers that don’t support any scripting languages will ignore the <SCRIPT> and <NOSCRIPT> tags and simply render what you have placed between the <NOSCRIPT> and </NOSCRIPT> tags. Thus, no matter what kind of browser a user has, your <NOSCRIPT> content will be displayed when it is appropriate.


FIGURE 2.9  The city of Sunnyvale, California, offers both framed and non-framed versions of its pages.


NOTE:  To keep your script code hidden from browsers that don’t support a scripting language, you should enclose the code in an HTML comment tag. This way, the raw code won’t be displayed on the browser screen.

Desirable Page Elements

As users traverse the Web, they become accustomed to seeing certain items on pages. They come to rely on these items being present to enhance their Web browsing experience. This section looks at a few common page elements that are also good end-user services.

Last Updated Date

  To learn how to automate your last updated dates, see “Microsoft FrontPage Components,” p. 281.

Everyone craves fresh content, so it makes sense to have some kind of “freshness dating” on your pages. A last-updated date tells visitors how recently the information on a page has changed (see Figure 2.10). Assuming they remember the last time they visited your page, regular visitors can use the last-updated date to decide whether any new content exists that they need to check out.


Server-side includes are another good way to have the server automatically stamp your pages with last-updated dates. See Chapter 32, “Server-Side Includes,” for more information.


CAUTION:  

Having a last-updated date can create image problems for you if you don’t keep refreshing your pages. Users will be unimpressed if they see a last-updated date of six months ago!



FIGURE 2.10  Investors in the New York Stock Exchange want the most up-to-date information possible, so it’s important to include date information on each page.

Contact Information

User feedback is important to your efforts to maintain and improve your pages. Many Web pages have contact information at the bottom, typically the email address of the Webmaster or the page author. Others take you to a separate HTML page to collect feedback (see Figure 2.11). These email addresses are often hyperlinked so that users can click them and compose a feedback message.


NOTE:  It is better to include your email address right in the hyperlink so that visitors can just click to send mail. That way, if someone is seeing a printout of the page only, she still knows where to send the feedback.

Navigation Tools

It frustrates users when they get that “you can’t get there from here” feeling. To avoid the Web equivalent of this, it is imperative that you place navigation tools on your pages. Depending on where users are, they will have different expectations about which navigation tools should be available.


FIGURE 2.11  You can contact the Peace Corps through a link at the bottom of its Web page.

A visitor hitting the home page of a site will most likely be looking for some type of clickable image or imagemap that can take her to the major subsections of the site (see Figure 2.12). A home page that is well designed will also include a set of hypertext links that duplicate the links on the imagemap. This enables people with text-only browsers, or people with image loading turned off, to navigate from the home page as well.


FIGURE 2.12  An imagemap on Motorola’s home page links you to all major parts of the site.

When on an inside page of a site, users typically look for navigation bars either at the top or bottom of the page (see Figure 2.13). Some pages have navigation bars at both the top and bottom so that the user has the option of using the closest one. In other cases, a page will have a set of links across the top of the page that point to the major areas of the site, and another set along the bottom of the page pointing to functional areas.


Try to keep your navigation links as close to the top of the page as you can. This enhances usability by eliminating the need for the user to scroll to find your links.


FIGURE 2.13  American Airlines provides links to major content and support areas of its site at the top of each page.


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