Install mod_security for apache2

Hello
i wanna install mod_security for apache2 and when tried apt-get install libapache-mod_security it doesn't work.
if someone can help to insatll it
thank you

 

Do you get an error message?
Which distribution are you using?

 

i'm using ubuntu 8.04
and the error is
E: can't find the package...

 

The package name is libapache-mod-security, not libapache-mod_security.