[eluser]Unknown[/eluser]
Well, I think so, this isn't supposed to be in a codeigniter forum, as it appears to be a jquery problem.
Don't use attr to set a class; use
addClass/removeClass,toggleClass.
Also, you are supplying 2 classes in the
toggleClass method, I am not sure you can do that.
And I think so, you need to supply a valid selector inside not(), whereas :eq() is not a complete css selector, its kind of a helper.
If after this it still doesn't work, try using
.eq() instead of
(":eq()") as the jquery selector.