I'm using the log4java, and I would like to write in a lot of log file, but I couldn't do it

this is my log4java.properties:
log4j.rootLogger=DEBUG,apFile,myLog
.....
log4j.appender.myLog=org.apache.log4j.RollingFileA ppender
log4j.appender.myLog.File=c:/genlog.log
log4j.appender.myLog.append = true
log4j.appender.myLog.layout=org.apache.log4j.Patte rnLayout
log4j.appender.myLog.layout.ConversionPattern=%d %-5p [%c] %C.%M(%L) - %m%n
log4j.appender.myLog.MaxFileSize=10000KB


and I do this en java class
Java Code:
Logger myLogger = Logger.getLogger("myLog");
myLogger.debug("message");

in the path: c:/genlog.log appears this messages generates by this line

Java Code:
protected static Logger logger=Logger.getRootLogger();
then I wrote this code:

Java Code:
log4j.rootLogger=DEBUG,apFile
and this warn returns to me
log4j:WARN No appenders could be found for logger (apbatchTask).
log4j:WARN Please initialize the log4j system properly.

any ideas?