Assuming you created the Nav Bars in WebStyle, in Frontpage double click the Nav Bar. WebStyle will open with the Nav Bar in top half of the window, click Menus and a self explanatory dialog box will appear in the bottom half of the window. Enter the relevant URLs in the appropriate spaces, press save, Make sure you are saving in the correct Project, press save and exit and you will be returned to FrontPage. When you upload make sure you upload the SOMETHING_files folder as well as your web pages