Music Creator 6 - Controllers in Piano Roll

Hello,
 
I am trying to edit various controller values in a song I am creating.  In Piano Roll view, I open the controller pane at the bottom.  By default, velocity is shown.  I would like to view other midi controller, but when I click the plus sign, the controller pane opens a second instance of velocity.  How do I show other controller data?
 
Thanks,
Patrick

Thank you for the response.  When I only have one controller (velocity), I only have the plus sign (no drop down to the right of it).  If I click the plus sign and add a second velocity controller, I then get a minus sign to the right of the plus sign.  There still is no drop down.  If I click the minus sign, the second velocity controller closes and I'm left with only one.  The words 'velocity' are not clickable either.  Finally, I've also tried right clicking to see if perhaps I'd get a context sensitive pop up menu, to no avail.
 
Any further ideas?

Thanks very much.  That did it.  Now I just have to find a list that correlates each controller with the numbers.
 
 

Thanks! I'll bookmark that link.