How do I change the resolution timeout?

[Lincoln Yeoh]

Hi,

Say I have BIND configured as a caching nameserver, how do I 
configure it to "give up" earlier and return a "FAILED/NX" response?

Currently it seems to take 30 seconds before it sends a response, but 
by that time most clients have timed out and they might also assume 
that the nameserver is the problem.

I would prefer the FAILED/NX response be sent to the clients earlier 
so that the clients can try to lookup an alternative site _earlier_.

Thanks!
Link.