Anyone here know PHP? Or may be the guy who created this Forum could help me out, because this forum is PHP right!

Well I have made a forum and I want to be able to convert the RETURN/ENTER key and convert them to < BR > or BRAKES. What is the code for a RETURN key?

I am using this, but I am not sure what I am replacing?
$message = ereg_replace("[]", "<br>", $message);