du saknar några prickar runt $_SESSION['UserID']
$edit = mysql_query("UPDATE users (Username, EmailAddress) VALUES('".$newusername."', '".$newemail."') WHERE UserID=" . $_SESSION['UserID']);
du saknar några prickar runt $_SESSION['UserID']
$edit = mysql_query("UPDATE users (Username, EmailAddress) VALUES('".$newusername."', '".$newemail."') WHERE UserID=" . $_SESSION['UserID']);