The raw 401 is the one responsible for the "No such nick" reply. Raw 311 is one of the /whois reply raws. There is no $chan in a /whois reply, so you'd have to previously store the chan in a %variable. Try this:
Code:
on *:input:#: if (/whois == $$1) { set $+(%whois.,$2) $target }
raw 401:*: if ($eval($+(%whois.,$2),2)) { msg $v1 $2 is not online at the moment. | unset $+(%whois.,$2) }
raw 311:*: if ($eval($+(%whois.,$2),2)) { msg $v1 $2 is online at the moment. | unset $+(%whois.,$2) }
I think this might help smile

Zyzzyx.

"All we are saying is give peace a chance" -- John Lennon