You use the Preview tab
(Windows) or Frame Preview tab
(Mac OS) to preview the entire contents of the frame set in the document window. You cannot edit the frame set or open linked pages in Preview mode. (To open and edit linked pages, double-click their page icons in the Frame Editor.)
If you're using GoLive for Mac OS, you can also use the Inspector to preview the content of individual frames in the Frame Editor. To preview a frame's content within the frame set, click the Preview Frame button
in the Frame Inspector. To hide the content, click the button again. Use the Preview Set button
and the Stop Preview button
in the Frame Set Inspector to preview the content of all the frames.
Note: GoLive for Mac OS cannot preview external URLs. You need to test external links with a browser.