Keeping track of who is telneting to my box

[Ali Ghaharbeighi <genesis oruks honk org>]

Hi every one,
I am using Redhat version 5.2.
I have a static IP address.
What I want to have is to see and keep track
of who is trying to telnet or ftp to my box.
I know the command last but it doesn't show the unwanted
persons trying to access.
I want to have like a program or script that runs
in the background all the time and creates me
a ASCII file and I can open the file and see who was trying
to access my box.
Is it possible or not?
And if it is how can I do that?
Any help is really appreciated.
Thank you