thank for reply, but im still learning and not clear ,can you clarify for me on how do i edit the line, for example what do i put to restrict user names to 20 characters ,while i get strtolower makes the name lower case , what sets it length

Yes you can https://github.com/opensource-socialnetwork/RestrictUsernames/blob/main/ossn_com.php#L23

Set the minimum 6 and maximum you wish.

Nice component, btw is there anything to restrict the user name length. or would that be a mysql data base setting i can do?

Thank you : )