HELP - AUTO COMPLETE

hi
i am using rails auto complete plugin.
I'm autocompleting over UserInfo Firstname as so
auto_complete_for :user_info, :first_name, :limit => 30
everything works fine.
but I want to filter out the first name given by auto_completer to those
which has conditions
:conditions => ["login !=?",'admin'])
I tried overriding the call to
auto_complete_for :user_info, :first_name, :limit => 30, :conditions =>
["login !=?",'admin'])
What is overriding the :conditions within the plugin so now,
it doesn't do auto_complete anymore but simply listing all first_name
except the admin's first_name.
Any Solutions to my Problem