Lightbox include

Hey!

I’ve got no problems installing the lightbox plugin. But, the moste annoying thing is that I always have to add the rel=”lightbox[roadtrip]” – tag to every picture I want to include into my blog.

Is there any way to make this automaticly?
I’ve tried to find a way in the PHP code, but I can’t find the place for inserting!

Sorry for my bad english, hope you’ll understand!

Thank you!
// Martin