[SOLVED] Restricting Characters in a Form

[eldorik]

Hey.

 

Does anyone know how to only allow specific characters in a form input?

I only want my users to have their names with letters A-Z and numbers 0-9 and not other symbols like * & ^ $ and so on.

 

Thanks.

[darkfreaks]

 

ereg_replace($username,$pattern,$replace);

$username=$_POST[username];

$pattern="*^$%&()#@!";
$replace="";

 

 

and so on