Location of Php error or log file

[mwm]

One of my web sites is running very slow. I don't know if its related to php but is there a php log file I can look at?

Thanks

[firepages]

check your php.ini, this should either point to a log file or mention syslog in which case look in /var/log/ , also if php is running as an apache module you may see php error messages in the apache error logs