log4j

Hi,

i want to use log4j with JOnAS. I follow the configuration guide and putt the
log4j.properties in $JONAS_BASE/conf and log4j jar file in
$JONAS_BASE/lib/commons. 
If I now uncomment in trace.properties the wrapper:
"log.config.classname
org.objectweb.util.monolog.wrapper.log4j.MonologLoggerFactory"
and comment the wrapper:
"log.config.classname org.objectweb.util.monolog.wrapper.javaLog.LoggerFactory"
I get the following execption:
"Cannot get LoggerFactory:java.lang.ClassNotFoundException:
org.objectweb.util.monolog.wrapper.log4j.MonologLoggerFactory"

What am I doing wrong?

Thanks
Mathias