Nagios starts, but I can't display nagios web page

I’m new at Nagios, sorry.

I originally installed a Nagios 3.0.6 rpm from Novell on my SLES 11, SP1 server. I then removed those packages to compile the latest version that would have standard paths. Here are the packages I removed from SLES 11:

nagios-plugins-nis-1.2-1.22
nagios-plugins-1.4.13-1.35
nagios-nsca-client-2.7.2-7.16
nagios-www-3.0.6-1.21.1
nagios-3.0.6-1.21.1
nagios-nsca-2.7.2-7.16
nagios-plugins-rsync-1.02-2.21
nagios-plugins-extras-1.4.13-1.35

I then installed Nagios 3.2.3, Nagios Plug-ins 1.4.14, and followed the Open SuSE Quickstart directions from here: http://nagios.sourceforge.net/docs/3_0/quickstart.html

When I attempt to run the Nagios webpage, I get a login prompt for user nagios. I use the nagios user and correct password to login, but it won’t take the login. It just puts up a new login box that is empty.

/var/log/apache2.log says:
[Tue Nov 09 08:35:14 2010] [error] [client ::1] user nagios not found: /nagios
[Tue Nov 09 08:35:19 2010] [error] [client ::1] File does not exist: /srv/www/htdocs/favicon.ico

/home/nagios/nagios.log says:
[1288887513] Error: Cannot open main configuration file ‘/etc/nagios/reload’ for reading!
[1288887560] Error: Cannot open main configuration file ‘/etc/nagios/reload’ for reading!
[1288893893] Error: Cannot open main configuration file ‘/etc/nagios/whq/reload’ for reading!
[1288893994] Error: Cannot open main configuration file ‘/etc/nagios/whq/reload’ for reading!
[1288894034] Error: Cannot open main configuration file ‘/etc/nagios/whq/reload’ for reading!
[1288973557] Error: Cannot open main configuration file ‘/etc/nagios/whq/reload’ for reading!

NOTE: The above /etc/nagios/whq is part of the directory structure from my original Novell rpm install of Nagios 3.0.6.

The error message from the Firefox browser after the login failure is:
Authentication required!

This server could not verify that you are authorized to access the URL “/nagios”. You either supplied the wrong credentials (e.g., bad password), or your browser doesn’t understand how to supply the credentials required.

In case you are allowed to request the document, please check your user-id and password and try again.

If you think this is a server error, please contact the webmaster.
Error 401

Can you help?

I found it. I needed to install php5. I installed php5 for Apache and php5 core and the web came up ok. Only took all day to figure it out. At least I can go home in a better mood.