Problems using log4j

[fred]

I want to use log4j but I have problems
My file log4j.properties:

Code:

log4j.rootCategory=WARN, C


log4j.appender.C=org.apache.log4j.ConsoleAppender
log4j.appender.C.layout=org.apache.log4j.PatternLayout
log4j.appender.C.layout.ConversionPattern=%-5p [%-24d] - %c.%m%n

#Appender sobre archivo (FileAppender)
log4j.appender.F=org.apache.log4j.FileAppender
log4j.appender.F.File=C:/service8.log
log4j.appender.F.layout=org.apache.log4j.PatternLayout
log4j.appender.F.layout.ConversionPattern=%-5p [%-24d] - %c.%m%n

my code:

Code:

static Logger log = Logger.getLogger(User.class);

log.error("error in …");

in console appears "error in..." but it doesn't generate the file.
what's the problem ?
thanks in advance

[katie]

write

Code:

log4j.rootLogger = WARN, C, F

instead of:

Code:

log4j.rootCategory=WARN, C

good luck