After deleting the indicated code, the following errors occurred:
Warning: mysql_select_db(): supplied argument is not a valid MySQL-Link resource in /Library/WebServer/Documents/worldmix/UserRegistration100/users_Registration.php on line 100
Warning: mysql_query(): supplied argument is not a valid MySQL-Link resource in /Library/WebServer/Documents/worldmix/UserRegistration100/users_Registration.php on line 104