There are two ways to create a frameset in Dreamweaver: You can select from several predefined framesets or you can design it yourself.
Choosing a predefined frameset sets up all the framesets and frames needed to create the layout and is the easiest way to create a frames-based layout quickly. You can insert a predefined frameset only in the Document window’s Design view.
You can also design your own frameset in Dreamweaver by adding “splitters” to the Document window.
Dreamweaver splits the window into frames. If you had an existing document open, it appears in one of the frames.
To split a frame or set of frames vertically or horizontally, drag a frame border from the edge into the middle of the Design view.
To split a frame using a frame border that isn’t at the edge of the Design view, Alt‑drag (Windows) or Option-drag (Macintosh) a frame border.
To divide a frame into four frames, drag a frame border from one of the corners of the Design view into the middle of a frame.
If there’s unsaved content in a document in a frame that’s being removed, Dreamweaver prompts you to save the document.