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Professional CSS: Cascading Style Sheets for Web Design, Second Edition by Mark Trammell, Dunstan Orchard, Ethan Marcotte, Cindy Li, Todd Dominey, Christopher Schmitt

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Appendix D. CSS Troubleshooting Guide

Even after staring at the monitor for what seems like hours, does everything appear fine in the code, but not when you press the Refresh button?

Relax.

CSS beginners and gurus alike have all been through this. Use this troubleshooting guide to save you from Refresh frustrations.

Validation

When you run into a problem, the first thing that must be done is ensure that your HTML and CSS syntax are correct. The syntax that Adobe Dreamweaver or Microsoft Expression generates can hide code while your design still needs to be checked.

If your Web development software does not come with its own validators (check your software's documentation for details), be sure to set the preferences so the Web development software excludes proprietary elements, such as center, so that the validator is checking the standard DTD.

This section describes Web sites for HTML and CSS validation.

HTML

For HTML validation service as shown in Figure D-1, see http://validator.w3.org.

The HTML validator from W3C.

Figure D.1. The HTML validator from W3C.

Once at this site, enter into the form the URL of the page that is causing you trouble. If you use the URL, make sure that the Web address is actually visible on the Web, meaning that the file is not behind a firewall or a password-protected zone such as an intranet. If your HTML file falls into one of those categories, use the upload feature provided by the validation ...

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