Ignore incoming call on V3

Is there any way to ignore (send to voice mail) an incoming call on a V3
with the flip closed?

I can do it with it open or closed with the bluetooth headset working.

Someone suggested that the answer is to press the voice button, but I've
tried without result. If one presses the smart key, the ringer is silenced,
but the call must go through it's don't answer cycle before getting forwarded.

All replies most welcome.