You can use JavaScript at the top of an HTML document to detect if a frameset is loaded and if not, load the frameset. If a window’s top property points to the window itself then that frame is the main frameset or document:
This is document #1
If that’s true in this case then the user has somehow bypassed the frameset that sets up your site’s navigational elements. Simply changing the window’s location property to the URL of the appropriate frameset HTML sets everything right. Also, this is a good way to check if your page is being displayed as part of someone else’s frameset and break out of it if necessary: