[RESOLVED] Detect if invalid chars are used

[OniLink]

Hi,

I am creating a register process and was wondering what is the best way to detect if the user inputs invalid characters for their username?

Thanks for any help,
~Oni.

[jsim]

Try regular expressions (Perl or POSIX compatible). It all in the PHP dox.

[OniLink]

Thanks jsim. I used:

preg_replace('`[^a-z0-9-_]`i','',ereg_replace(" ","_",$_POST['username']))