Amadi, the reason it changes terrain is because when you remove blight, it doesnt necesarily revert back to the terrain that it was before. In this case, it turns into rough dirt. That's a complication with using Blight, I guess. Anyways, thanks for comments. I won't be able to do any coding, since my good computer is in the shop for the week. If you need me to change it badly, just PM me and I'll get on it as soon as I can. Thanks.
Edit: After reading your post again, I realize you said it turned the whole map to rough dirt. Yeah, that's because I didn't know in what unit the terrain change function worked. I thought it was normal units, so I put in 400 (or something). But now I see it meant squares, so you'll have to mess around with it, or I could. Sorry for the inconvenience.