See it in action! Actual demos you might actually use, perhaps.

Simple "hello world" example.

search: <input type="text" name="search" class="jsrequired" /><br /> <input type="submit" value="go" />

Here's a single field example that is required and it must be a US or Canada zip code.

zip: <input type="text" name="zip" class="jsrequired jsvalidate_uscanzip" /><br /> <input type="submit" value="go" />

This is an example of a very simple "contact us" form with an example of a custom error message.

(* means required) *Your Name: <input type="text" name="visitor" class="jsrequired jsvalidate_alpha" /><br /> *Your Email Address: <input type="text" name="email" class="jsrequired jsvalidate_email" alt="We require a valid email address." /><br /> Subject: <input type="text" name="subject" class="jsvalidate_alphanum" /><br /> *Your message:<br /> <textarea name="message" class="jsrequired" rows="5" cols="30"></textarea><br /> <input type="submit" value="Send information" />
(* means required)
*Your Name:
*Your Email Address:
*Your message:

Not impressed yet?

Here's the first example formatted just a little better.

search: <input type="text" name="search2" class="jsrequired {errorLocation:'none'}" /> <input type="submit" value="go" /> <span id="jsvalidator_search2" class="jsvalidation">You must enter a search term.</span>
search: You must enter a search term.