[1] Install PHP
[root@www ~]# yum -y install php php-mbstring php-pear
[root@www ~]# /etc/rc.d/init.d/httpd reload
Reloading httpd: [ OK
[2] Make PHP test page and access to it with web browser. It's OK if following page is shown
[root@www ~]# vi /var/www/html/index.php

print "PHP Test Page";
?>