How to set the Error Reporting to a lower level in Joomla! 1.5
Log into the back end usually the following URL http://www.yoursite.co.za/administrator using your admin username and password.
Once logged in click on SITE->GLOBAL CONFIGURATION at the top menu bar.
Click on the SERVER TAB
Under SERVER SETTINGS set ERROR REPORTING from e.g. MAXIMUM to SYSTEM DEFAULT or as you prefer.