Nagios 403 Forbidden Error Message You don’t Have Permission

After I installed the Nagios in my vps I open the Browser then I try
http://IPADDRESS/nagios

While I try I got the following Error message.

You don't have permission to access /nagios/ on this server.

Apache/2.2.3 (CentOS) Server at 74.86.173.70 Port 80

So I go the error log file

/var/log/httpd/error_log and I go through the log file.
You need to perform the Trouble shutting Depends upon the error message from the log file.

Error Message: [Fri Jul 16 19:53:27 2010] [error] [client 61.11.75.40] Directory index forbidden by Options directive: /var/www/html/
Solution: if you get the error message like these error message clearly says. Client try to read the index file But it can’t so create the index.html file under these document root directory.
/var/www/html touch index.hml
Then try it it will be solve.
If index file is  already present like index.php But unable to read index file.
Then you need to install php
#yum install php* 
Here index.php file is locate under the nagios Document Root Directory
/root/nagios-3.2.3/html/index.php 

Error Message: [Fri Jul 16 19:53:27 2010] [error] [client 61.11.75.40] Directory index forbidden by Options directive: /usr/local/nagios/share/
Solution: you need to create the index files under the nagios document root directory /usr/local/nagios/share/
/usr/local/nagios/share/ touch index.hml
 Directory index forbidden by Options directive: /var/www/html/
Directory index forbidden by Options directive: /usr/local/nagios/share/