preventing hotlinking

I modified the .htaccess file, but that resulted in blocking the entire website/page... Anybody have advice on how to prevent hotlinking? Thanks in advance.

fourth hit when googling for "hotlinking":
http://www.htmlbasix.com/disablehotlinking.shtml

eyebex ~~ Thanks for your reply! I googled and tried the generator on that website a few days ago, before I came here for advice. In fact, it was the code from that website that messed up my web pages! I did figure it out last night, though, after going to a FrontPage forum and tweaking the formula some more. I'm all good now.

Again, thanks for your very helpful response!

ladyshine