Thanks to Joseph and Nate for helpful answers. A stupid question: I do not receive your mails although already subsribed to this list. I read your answers on mail archive. I set up my account to receive email from list but it seems not work. Chau -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20090513/4e95957a/attachment-0004.html>