reassign running button to Button.PrimaryThumbstick

hi 
I can't find a way to change the button to run on the touch controllers
I found the:   

 // Run!                moveInfluence *= 2.0f

I changed it to:  If (OVRInput.Get(OVRInput.Button.PrimaryThumbstick)  tho, don't know how to set it back!!!!!

but it did't work

plzz help me with this
what do I need to change