note 81625 rejected from function.preg-match by nlopess

Note Submitter: djevertrue at yahoo dot com ---- Can I user this to match a partial username ? for example I user if (!preg_match("/^[a-zA-Z\d\-_]+$/i", $username)) { blah blah if I want to check if a username has special characters or spaces. what is wanted to do something like: user enters username test username test is a banned username so how would I block anything that has test in the username ?