I followed there instructions:
http://www.osnews.com/story.php?news_id=2949
And everything went fine.I installed the kernel and I booted.But there was a big problem:in the errors it said that there are no eth devices and because I have cable net through the an USB modem I cannot connect to the internet!(I cannot do anything without the net ) I enabled everything almost everything in the Network Place and the USB but the net isn't present.Tomorrow I will reinstall the debian and try to compile another kernel and the net working.Any suggestions where I did mistake ? And can you tell me what's the default config ot the bf24 2.4.18 kernel of original debian ?
Thanks to all

You already have the default bf24 kernel config file. It's in the /boot directory.

Actually, if he did the stuff through make-kpkg and installed the .deb generated an entry to the old kernel should be in LILO, shouldn't it?
A good idea when recompiling kernel is to reuse the old .config file (except for 2.6.* as it doesn't help at all....) in your /boot directory you'll find a config-something-related-to-your-kernel and you just have to copy it to the /usr/src/linux directory changing its name to .config... so you can run make menuconfig (or whatelse you're using) and you'll be reusing the same options from your previous kernel. And this statement is (almost) always true: If it worked on the last one, with new one it should work too. (from 2.4.* to 2.6.* turns out to be a big exception here). So... I hope I could help'ya

thanks a lot....after I fix my linux I will write about the results :P