[kh99]

You can only use a small set of functions in conditionals (see the manual here): http://www.vbulletin.com/docs/html/m...n_conditionals (like the list in the error message)

So the way around that of course is to make a plugin for the code which sets a variable that you can check in your template.

Something I just noticed recently - you can actually allow other functions in templates (see the bottom user comment on the above page), but that also requires a plugin.