that works great, except:

but I was also wondering is there a way around if the IMG call was in lowercase (sorry, I neglected this before). I guess something like (IMG|img)...?

Secondly can you please explain exactly what is happening here (it makes it simpler for me to not need to ask the next time when something similiar comes up). I've been referencing a couple of books and I don't think I've seen before the "=" used in the sed command. The man page doesn't tell me much either.

Thanks again, much appreciated!