trigger with an if statement

hey i wanted to know if i could make a trigger "gossip hello" to someone when they get on mud. but the thing is that i dont want to tell every person that gets on hello. so is there a way to make an if statemtn that runs a test to see if that name is ok, and if it is, then gossip hello?

What does it look like?

"Fred has joined the MUD?"

Make a trigger that matches on that.