redmine 2.1.2 stack - porting plugin with autocomplete field

I'm porting a custom plugin from redmine 1.3.2 to redmine 2.1.2 and we are using the bitnami stack with redmine 2.1.2 to do so.

with redmine 1.3.2 all is ok, now i have a problem that blocks me to proceed: the autocomplete functionality doesn't work anymore. i have a partial with a 'text_field_with_auto_complete' tag, defined the auto_complete_for_xxx function in my issue controller and define the "match 'issues/auto_complete_for_system_name', :to => 'issues#auto_complete_for_system_name'" in my routes.rb.

When i start typing in the text field nothing happens: how can i check if my Ajax funcionality is installed ok?

How can i check if my bitnami stack is using "prototype" or "jquery"?

sorry but i'm really new to redmine/rails 3 etc...

thanks in advance

could you plase