[jQuery] (validate) preclude, deny, disallow or prohibit URLs from submitting

[jQuery] (validate) preclude, deny, disallow or prohibit URLs from submitting


Hi all sorry - I can't figure this out and I'm a little thick.
I'm using the great validation plug-in from bassistance and would like
to use it to stop a form submitting contents of a *required* comment
field when a URL is present in there. [Getting spam links submitted to
a contact from]
I've previously managed to hack the plugin to allow spaces and a
leading "+" for phone numbers but this is beyond me as I'm not trying
to extend but rather invert the function. ?
I've been trying for two hours and can neither find anything out there
- or hack anything that works.