log4j warning . i am getting this warning

log4j: WARN No appenders could be found for category (org.apache.struts.util.PropertyMessageResources). log4j:WARN Please initialize the log4j system properly.i am getting this warning while starting the tomcat.please help me on this.
[255 byte] By [brucelia] at [2007-11-27 0:50:41]
# 1
This is not a Log4J forum check here: http://logging.apache.org/site/mailing-lists.html
appy77a at 2007-7-11 23:20:59 > top of Java-index,Enterprise & Remote Computing,Web Tier APIs...