is_unique func of form validation in codeigniter is not working

Question

Currently I am using codeigniter 2.0.2 version. I have searched all files but not found declaration of is_unique function for form validation where I can check either username is already exists.

Should I create it my self, Is it best or download some other version ?

Answer 1

is_unique was added, if I recall, in 2.1. So download that.