Help, installing nagios 3.0.3 on Ubuntu

I am trying to install 3.0.3 on ubuntu 8.04. I am following the install guide provided by nagios but when i get to the poing where i run /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg i get bash: /usr/local/nagios/bin/nagios: No such file or directory.

What am I doing wrong and what can fix it?

It looks like your install is in a different place

cd to the actua directory were the nagios executable is and run: ./nagios -v nagios.cfg