All of the files in the ui.defaults directory may be over-written when
upgrades are performed. You should not edit any of the files in the ui.defaults
directory or sub-directories.

You can over-ride the CSS rules by adding duplicate rules to the CSS file in 
your site skin directory.

If you need to add images or JavaScript functions to your site, add them to 
the images and/or JavaScript directories in your site sking. SkyBlue will load 
your site skin *after* the system defaults are loaded so your style rules will 
take precedence and your images and JavaScript functions will be accessible to 
the user-agent.