note 102533 added to function.preg-match

Please, help me! What is the valid regex for filtering logins? The login consists only from characters a-z A-Z, 0-9 but there is no whitespaces. for example somebody - valid login somebody123 - valid login 123somebody123 - valid login et cetera some body - invalid login these regexs doesn't works for me /[0-9A-Za-z]/i /[0-9a-Z]/i /[0-9a-Z^ ]/i /[0-9a-Z^\s]/i i use this code if (preg_match("/[0-9A-Za-z]/i",$login)) { $ok=1; } ---- Server IP: 69.147.83.197 Probable Submitter: 178.219.41.66 ---- Manual Page -- http://www.php.net/manual/en/function.preg-match.php Edit -- https://master.php.net/note/edit/102533 Del: integrated -- https://master.php.net/note/delete/102533/integrated Del: useless -- https://master.php.net/note/delete/102533/useless Del: bad code -- https://master.php.net/note/delete/102533/bad+code Del: spam -- https://master.php.net/note/delete/102533/spam Del: non-english -- https://master.php.net/note/delete/102533/non-english Del: in docs -- https://master.php.net/note/delete/102533/in+docs Del: other reasons-- https://master.php.net/note/delete/102533 Reject -- https://master.php.net/note/reject/102533 Search -- https://master.php.net/manage/user-notes.php