php link informix problem

I have a mysql+php+apache server,It must have some program to call another informix database,I don't know how to configure my php,anyone have good resource help me??

why my phpinfo() MYSQL_LIBS no value

I use redhat8.0 and default install RPM Mysql,but I don't install php and apache default. After the linux setup,I compiler the php4.3.1 and apache1.3.27 tar.gz,but the phpinfo() MYSQL_LIBS and MYSQL_LIBS "no value"!!! why? how do I fix this problem??? thankx~~~ -- MySQL General Mailing Lis