midi surface controller

hi there
i am trying to set up Ardour so that i can use the surface controller option to produce a live set. I am using a Behringer rotary 2000 controller which works fine with jack. However when I try to use ctrl middle cick an ctrl to map midi messages nothing happens. As in the prompt comes up to move a knob or press a button etc but Ardour does not recoginise the action.
So can anyone tell me what I have to set up in the edit / preference / surface controller menu oor in jack to get midi to work.

Did you read the section on setting up MIDI in the manual?