Fedora 18: changing Ethernet interface name.

I want to change em1 to eth0 AND em2 to eth1 on my server installation, I renamed them in the NAME filed inside (ifcfg-em1 and ifcfg-em2):

Then I renamed ifcfg-em1 and ifcfg-em2 files to ifcfg-eth0 and ifcfg-eth1

BUT when I type ifconfig, I still see the naming as em1 and em2 !!!