David Scotson

Have you tried the Web Developer Extension for Firefox? As well as many other excellent tools it allows you to "Validate local HTML" which automatically takes the page you are looking at and submits it as a form to the W3C validator (i.e. the equivalent of cutting and pasting the source).

On the other hand, I believe the reason you can't validate internal pages is because the validator isn't logged in as a user and so gets redirected to the login page. I believe you can create a special login for it, but can't remember how off the top of my head. Ah, found it, Martin suggests creating a user called w3cvalidator.

I don't know how these activities would go over in a classroom setting but:

• showing a range of images and how they appear to people with color blindness (a bonus here is that you are likely to have a colour blind student given it is present in 1 in 10 males). Interesting things you could show are animal camoflage patterns that only work in black and white, or those dot patterns for color-blindness testing, and standard warning/road signs. You can run images and websites through VisCheck to simulate color-blindness and demonstrate that some images (e.g. the dot test) lose meaning, while others (e.g. warning signs) are specifically designed not to. I believe the VisCheck program has trouble with modern CSS designs but you could run it on an image of the webpage.

• getting students to use a screen reader e.g. JAWS to complete simple tasks on the web with the monitor turned off to simulate total blindness. I'd guess total failure for these tasks, as there's a bit of a learning curve with these things.

• viewing website with tools like Lynx gives some idea of what blind users will hear. There used to be an online simulator but it blocks access to most sites because of abuse. It's available for most platforms though. Maybe the firefox add-on Fangs which seeks to provide a textual equivalent to what Jaws users would hear would be interesting. (It may be too advanced, but pointing out that what a blind web surfer hears is the same as what Google indexes is an important point).

• you could find some DHTML/AJAX sites that require some degree of hand-eye co-ordination (particularly anything with heirarchical pop-up menus) and challange the students to operate the sites with the mouse using their left-hand (or right for left-handers). You should find that most will just about get by with Windows or Mac OS X gui's but that most websites that imitate these GUI conventions will fail miserably for those with poor motor ability.

• you could try accessing different sites via a mobile phone or PDA browser. Generally accessibly sites are better for this purpose too.

• after going over the basics you might want to get students to rank sites purely by letting them see what a site looks like and perhaps use briefly before ranking them in order of accessability. By choosing some beautiful sites that are accessible and ugly sites that are not you could challenge the assumption that accessible necessarily equals ugly.

Also, Mark Pilgrim's Dive into Accessibility is a great introduction to the topic. It might be a bit much for your students but I'd imagine there's a lot of great material there that could transfer without much work, as the tone is very straightforward and down-to-earth.

The problem (translating from the obscure error message: mod_security-message: Access denied with code 500. Pattern match "../../") is that the url you are accessing to play that mp3 includes the sequence "../../" which means "go down 2 directory levels".

It's sometimes possible for people who are trying to get to places that they shouldn't have access to use this trick to bypass security checks and dig about the file system so that server is rejecting it on principle (even though in this case it looks totally harmless and proper for it to be looking for that particular file).

It could possibly be considered a bug in the multimedia filter and that it should always use the full URL starting "http://your.moodle.url/blah/blah blah..." but it depends on how that's interacting with the original file link. It probably just uses what's there in the html in Moodle, so if you change the original download link to avoid needing "../../" it should start working, I think.

(there also seems to be a sub-error, that the security code is triggering a 500 error a.k.a Internal Server Error, but the page it should display in that case /home/efleg/public_html/gakuen/500.shtml doesn't exist.)

It's probably worth mentioning that there are a great many similar programs available and while Navicat looks very slick and easy to get into for those who are less experienced with databases and is relativley inexpensive, people may wish to look at options that are free for personal/educational use or, even better, support open source alternatives.

On Mac OS X I've occasionally used CocoaMySQL which seems to be generally well reviewed.

I'd imagine that others have favourites and recommendations they could pass on too.

I think you are missing a hash (#) on the second line, try:

#left-column .hidden .header,
#right-column .header
{
    background: url(right_side_block.gif);
    border-bottom-color: #dddddd;
}