VB requires MySQL functions in PHP????

[Orp]

I'm building my first server where I've had to do it all. Install the OS, PHP, MYSQL etc....
So I've gotten far enough to start my VB install and after entering my customer number I get:

vBulletin 3.7.3 requires that the MySQL functions in PHP be available. Please ask your host to enable this.

Can you give me a clue how to enable these functions?
Thanks!!!!

[Wayne Luke]

http://us2.php.net/manual/en/mysql.installation.php

[Orp]

Thanks Wayne. That helped.

So I did the yum install php-mysql and thatworked fine.
I'm still getting the error message though.

double checked I had run the right command by running it again ...here is the output:
[root@netcarstop ~]# yum install php-mysql
Setting up Install Process
Parsing package install arguments
Package php-mysql - 5.1.6-20.el5_2.1.i386 is already installed.
Nothing to do

However I still get the error message saying that

vBulletin 3.7.3 requires that the MySQL functions in PHP be available. Please ask your host to enable this.

I am the host .... Any ideas on how to get past this?

[Floris]

did you restart httpd after you installed it?

[Orp]

I had to restart apache after running the yum install php-mysql command.
Once Apache was restarted I got past that error message.

Edit to add:
Thanks Floris. You got it right. I had not restarted apache. Duh!!!!!