autocomplete for users not working

Ive searched the forums and all that stuff, and i cant find a fix for this. On the autocomplete for the users, when u click a username, it just says undefined in the box. I looked in the error console and it says el.addClass is not a function. Can you help me?

Do you use Joomla 1.0 or 1.5?
Do you have MooTools 1.1 or 1.2 enabled (or Auto or Disabled)?

It sounds like that the MooTools Javascript files have not been loaded.

Post edited by: slabbi, at: 2009/07/02 23:01