Log file /var/log/nagiosgraph.log not writable

Hi
I had configured nagios and it is working fine , now I wanted to make nagiosgraph work for me, I had kept the “nagiosgraph

try chmod 777 to nagiosgraph.log (not .conf) and see what happens…
is apache running as nobody? (sometimes it runs as www-data or other users…)

Luca