[jboss-user] How to reduce/disable log messages?

This seems to be a simple enough task, yet I haven't found any instructions on how to do this. I tried to edit default\conf\jboss-log4j.xml, but that doesn't help a lot. For example, I set org.jboss.system.server.Server to ERROR, and still I get INFO messages. I know this is one of the log4j files being used, because if it has any invalid configuration, an error message will show up in the console. thanks