Reply to Help with FX mappings

Okay so I just switched to Traktor pro 2 and i would like to be able to use the FX on my Hercules mk4. I have managed to map the FX to the nit but I would like it to were I activate and hold the FX button, I can then use the Tempo knob to control the FX. I'm sorry if this doesn't make sense, but please help