how to write stdout (System.err.println...) to error log ?

Hi, I use Sun Java System Portal Server 6 2005Q4 for windows 2003 server. How can we setup the error log file and write stdout (System.err.println...) to error log from portlet ?where is the error log file located ?Can someone help me ?Thanks!
[285 byte] By [ili1259cheng] at [2007-11-26 10:23:38]
# 1
Look for System.err in your app/web server logs.
unni_blr at 2007-7-7 2:25:01 > top of Java-index,Web & Directory Servers,Portal Servers...