how to add dynamic menu menuitem and sub menu item

I have used menu class to make menu in master page of my application.
In menu and menu items comes from database.
Menu could able to see statically and menu items could be seen dynamically, when cursor is on any particular menu.

Now further i want to add child s in that menu items. So such kind of application from where in menu child s would came from database how to do?
In master page?

could you suggest me code of snippet?

-komal

Thanks & Regards
Komal Khatkole.