Horizontal menu with drop down

I have a white horizontal menu and I need a border around the main link and around the drop down, with the border only around the whole main link and drop down outside. Not divided

Also the single links without drop down should not have a border.

This will take a bit of CSS work. Please post a like to the code you have so far, or at least post the full code here, but all in one ‘page’ please (with CSS in the head).