apache is running but is not responding to http request

Hello

on Centos 5.3, httpd is running properly (I checked with ps -A), the DNS entries are properly made (for instance ping example.com hits the right IP) but I cannot access the pages. I am using Virtualhost.

httpd -t returns Syntax OK.

SO, all is good except I don't see the websites.

Any idea of what I might want to check?

Thanks