add VM Memory or some args in tomcat

My path ~/Applications/apache-tomcat-6.0.36/bin

My PC 'system is Ubuntu 10.04.

Modify the file catalina.sh 

found the code in  catalina.sh 

if [ -z "$LOGGING_MANAGER" ]; then
  JAVA_OPTS="$JAVA_OPTS -server -Xms128m -Xmx128m -Dfile.encoding=GBK -Djava.net.preferIPv4Stack=true -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager "
else
  JAVA_OPTS="$JAVA_OPTS $LOGGING_MANAGER"
fi

 You can see "-server -Xms128m -Xmx128m -Dfile.encoding=GBK -Djava.net.preferIPv4Stack=true ".

You can add  vm's args in here