Tracing low level signals in Altera's native simulator in Quartus II Version 9.0

I have an old project that I have to fix and picking up form someone else. I have a stimulus file (.vwf) that I simulate. When I run it using the Quartus II simulator the resulting waveform window comes up but I only get the top level input/output pins. How can I tell the simulator to trace and display internal net in modules in the schematic below the ​top level.

The design is in schematic format with some AHDL module.

Thanks,

Oscar