I'm not sure that makes much sense

If your code is displayed, it sounds like you've got everything in .txt (text) files, not .html files. This sounds like one of those "gotta be there to believe it" kinda things. You need a frameset, and in the frameset you'll call up, say, two other .html documents which will go into, say, a left and a right frame. So, to start with you'll need three documents. A frameset document, and two documents to fill the frames.