[newbie] Need help

[New Star Service Co.]

I have 2 harddrive one is Linux(slckware,mandrake)and next is Dos(win98).
today i install redhat6.1 over slackware. my installation ok but redhat
run default and no any other OS here. why ? i installed  LILO but i don't
know what happens. LILO prompt only shown redhat there.

my lilo conf is like that under redhat:-

boot=/dev/hda
map=/boot/map
install=/boot/boot.b
prompt
timeout=50
default=redhat

image=/boot/vmlinuz-2.2.12-20
        label=redhat
        initrd=/boot/initrd-2.2.12-20.img
        read-only
        root=/dev/hda2

other=/dev/hdc1
       label=dos

pleas help how can i conf my all OS under LILO.
for your information now i have three OS: Mandrake6.1,redhat6.1 and Dos

and also please inform how can i use RH kernel for RH and Mandrake for Mandrake
 need help.
partha.