Many websites use framesets containing two or more frames .
Unfortunately, even if a page is intended for viewing within a frameset only, visitors sometimes load it in the top-level browser window. This may be the case, for example, if they arrived from a search engine or if they bookmarked your page and then clicked on the bookmark. Such visitors may easily get lost, unless your pages provide some mechanisms for restoring the proper frameset automatically. Among these mechanisms, one of the best is AutoFramer .