in reply to Exact pattern match?

Remember that /yes/ will match 'yes' as well as 'yessir' and also 'grayest' - what you need is word boundries: \b

So change "yes|no" to '\byes\b|\bno\b' - and notice the single quotes - NOT double quotes.

And we don't rock - we RAWK!!

Jeff

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
F--F--F--F--F--F--F--F--
(the triplet paradiddle)