Can't find header files

[David Mendalski]

I'm a newbie using Mandrake 10.0, MySQL 4.0.18, which was installed via Mandrake's software installation program, and PHP 4.1.1. When configuring PHP I am adding --with-mysql=path/to/mysql. The problem is I get an error message that says it can't find the header files. I've tried these with paths with the same result:
/usr/bin/
/usr/sbin/
/usr/share/
/var/lib/mysql/

The MySQL Manual |2.1.2 Installation Layouts says the header files should be in /usr/include/mysql if RPMed, or /include/mysql if from source. On my system /usr/include/ has no directory or files named mysql in it and there is no /include/mysql directory. I've manually searched through all my directories for something that looks useful, but to no avail I come up empty. Also, I haven't been able to find anythng that tells me what file names the headers are contained in. I've also tried starting MySQL with the command #safe_mysqld & in a number of directories but get the "command not found" response.
Can anyone point me in the right direction to resolve this?
Thanks a million
David