Web browsing is all about links between pages. To make something a link to a page in your Freeway document, select it, click the ‘link’ popup menu item at the bottom of the document window, and choose which page to link to. What you select can be a graphic object or some text. However, you can’t use an HTML box itself as a link, only some selected text within it.
Alternative methods are dragging a page icon from the Site panel down to this Link popup menu, and going to Edit > Edit Hyperlink. This last option provides a wide range of options, including links to external sites. Remember to include the full path including http:// for all external links.