网页上显示这个Warning是什么意思？该怎么处理

网页上显示这个Warning是什么意思？

SQL code

Warning: mysql_connect() [function.mysql-connect]: Can't connect to MySQL server on 'localhost' (10048) in D:\APMServ5.2.6\www\htdocs\config.php on line 19Warning: mysql_select_db(): supplied argument is not a valid MySQL-Link resource in D:\APMServ5.2.6\www\htdocs\config.php on line 20Warning: mysql_query() [function.mysql-query]: Can't connect to MySQL server on 'localhost' (10048) in D:\APMServ5.2.6\www\htdocs\config.php on line 21