Database Array Question

I'm new to PHP and was wondering if there's any better way of retrieving the records from the query other than using an array (This query will only return 1 row): $auth = mysql_query("SELECT username, userlevel, password, email FROM users WHERE id = '".$_SESSION['uid']."'"); while ($row = mysql_fetch_array($auth)) { $password = $row['password']; } Also, can anyone tell me what the relevance of adding '!' is to an if statement eg. This: if(!isset($_SESSION['uid'])) Instead of this: if(isset($_SESSION['uid'])) Thanks -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/ -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/