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A.3. Online Communities

One can read only so much before it comes time to join a discussion and ask some questions. There are two major venues for discussions about CSS, but each is concerned with a specific type of discussion -- so make sure you go to the right place.

A.3.1. comp.infosystems.www.authoring.stylesheets

This Usenet group, often abbreviated as ciwas (pronounced "see-wass"), is the gathering place for CSS authors. A number of experts in the field check this newsgroup regularly, this author among them, and all are there for one primary reason: to help new CSS authors over the hurdles that learning any new language will generate. The secondary reason is for the spirited debates that occasionally erupt over some aspect of CSS, or a browser's implementation thereof. Rather unusually for a newsgroup, the signal-to-noise ratio stayed fairly high for the last few years of the 1990s, and will with any luck continue in that vein.


Anyone who wishes to be involved in discussing the future course of CSS, and to clearing up ambiguities in the specifications, should subscribe to this list. The members of the list are all, in one fashion or another, interested in making CSS better than it is

Web-based applications are similar to app servers, except for one thing: Web-based applications don't have client apps, instead they use web browsers on the client side. They generate their front ends using HTML, which is dynamically generated by the web-based app. In the Java world, Servlets are best suited for this job.

Web-based apps might themselves rely on another app server to gather information that is presented on the client web browser. Also, you can write Servlets that get information from remote or local databases, XML document repositories and even other Servlets. One good use for web-based apps is to be a wrapper around an app server, so that you can allow your customers to access at least part of the services offered by your app server via a simple web browser. So web-based apps allow you to integrate many components including app servers, and provide access to this information over the web via a simple web browser.

Web-based apps are very deployable, since they don't require special Java VMs to be installed on the client side, or any other special plug ins, if the creator of the web-based app relies solely on HTML. Unfortunately, this can restrict the level of service that can be offered by a web-based app when compared to the functionality offered by custom clients of an app server, but they are a good compromise when it comes to providing web-based access to your information. In fact, in a real world scenario, both a web-based app and app server may be used together, in order to provide your customers access to their information. In an Intranet setting, you might deploy the clients that come with the app server, and in an Internet setting it would be better to deploy a web-based app that sits on top of this app server, and gives your customers (relatively) limited access to their data over the web (via a simple web browser).

already. Please note: www-style is not the place to ask for assistance with writing CSS. For help with CSS authoring problems, visit ciwas instead. Questions beginning with "How do I ... ?" are frowned upon by the regulars of www-style and are usually redirected to a more appropriate forum such as ciwas. On the other hand, questions that begin "Why can't I ... ?" or "Wouldn't it be cool if ... ?" are generally welcome, so long as they relate to some ability that appears to be missing from CSS.

Messages to www-style are only accepted if the sender is already subscribed to the list. In order to subscribe, send email to with the word subscribe in the subject of the message; to unsubscribe, send email to with the word unsubscribe in the subject of the message.

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adjacent list items is 15 pixels, not 25. This is because along thevertical axis, adjacent margins are said to be collapsed. In otherwords, the smaller of the two margins is eliminated in favor of thelarger. Figure 7-16 shows the difference betweencollapsed and uncollapsed margins.

Figure 7-16

Figure 7-16. Collapsed versus uncollapsed margins

Correctly implemented user agents will collapse the verticallyadjacent margins, as shown in the first list in Figure 7-16, where there are 15-pixel spaces between eachlist item. The second list shows what would happen if the user agent situation becomes.

Figure 7-20

Figure 7-20. The dangers of document-wide negative-margin rules

Using negative margins with block-level elementssuch as these can quite obviously be dangerous and is rarely worththe trouble -- but it can also be rewarding. It takes a good dealof practice, and many mistakes, to learn to tell the differencebetween the two.

to support this behavior. There is also no defined behavior to say whether the foreground content of a previous line appears above the background of a succeeding line, or is overwritten by that background. Negative values are not permitted.


padding-bottomIE4 P/P IE5 P/Y NN4 B/B Op3 Y/-

This property sets the size of the bottom padding of an element, and this padding will "inherit" the element's background. Negative values are not permitted.