Eregi not working

[Napster]

I am trying to valuate a simple string that a user enters to make sure that it only contains letters, numbers, underscores and dashes. The current code I have is...

if (!eregi("^[a-z]{3,50}",$NewUserame)) message("Your Username does not consist of valid characters.");

Where $NewUsername is the username they entered in and Message() is a function I built myself.

If I put in something like: Josh$@$

It will pass that and say it contains valid characters when it does not. It is probably something wrong with my parameters but I am not sure. Any helps would be appreciated. Thanks.

[Weedpacket]

You're missing the end-of-string '$' on the end. But it would be a lot more efficient to check the length separately with strlen(), and then just look to see if there are any invalid characters. Just one would be enough for it to fail:

[^-a-z_0-9]

(For random input it would only have to check half as many characters.)