banning IP ranges

I have a site and want to block some users by their IP.

I can block users by with a single IP, but want to block users belonging to an entire IP range.

I have entered the specific IPs and IP ranges in a database and the PHP page interogates this database when a user accesses the page.

It's okay if the user has an IP specified but difficult when the user is part of a blockd range.

Does PHP have a way of reading an IP and determing if it is part of a specified IP block or not?

Thanx

Instead of using dotted IPs, use their integer (or 'long' to be exact) format to compare:

Diego

Hey Diego.

Just want to say thanx man. This works fine.

many thanx