The steps to create the cross-frame menu are as follows:

1. Click Global > Cross-Frame in the tasks panel to show Cross-Frame panel.
   
2. Check "Create Cross-Frame menu", and then select popup direction of the sub menu.
   
3. Fill the left and top frame name in the navigation frame box; and main frame name "main" in popup menu box .
   
   Left Menu Settings
   
   
   Top Menu Settings
   
   
4. Publish the menu into the navigation frame, that is the page where the menu shows. Click the button "Publish > Publish..." to publish the menu into the page. First, copy and paste the header code and body code to the page; and then save the resource files to the same directory with the page.
   
5. Save the frameset page and preview the menu crossing frame to show its popup menu.
   
   Note: To edit the menu again, just open the .pgt file of the menu in the program and click Publish to publish the menu again.