Network install, floppy only

I realize that this seems old hat for many of you, but we are having difficulty creating this. We would like to have a floppy somehwhat like RedHat's "bootnet.img" which can be used to boot a system and the system will begin an installation from an http server. No CDROM required. I've looked at the /boot/bootdisk file, and I see no config file that will let me edit to point it at the server. Obviously I am missing something (probably simple), but I'd appreciate it if someone could "give me a clue". Jon R.