Connection Failure PHP - MySQL

I am receiving the message WARNING MySQL Connection failed: Can't connect to MySQL server through socket '/var/lib/mysql/mysql.sock' (111).

I have been following the script 'Setting Up Database Driven Websites' by Ying Zhang posted on this website and all was well up to the point of executing the index.php3. That is, MySQL is working and the <? echo "Hello World"; ?> script to verify that PHP is functional worked.

I did a global search on 'mysql.sock' and found only 1 which is in /tmp/mysql.sock. Based upon the date/timestamp it was either created or touched by the 'Hello World' script mentioned above.

Software: Mandrake 6.0 (RedHat 6.0),
MySQL 3.23.2, PHP 3.0.8, Apache 1.3.6.

I only installed MySQL, as PHP3 was already in Apache. After checking all the conf and ini files of which I am aware, I am at a loss as to a remedy. Can anyone help?

Thanks in advance.

If you installed php, then added mysql later, then you didn't ./configure --with-mysql when you config/made the php_module. You will likely need to do this and remake apache.