Can someone here direct me on how to develop a menu like the one on www.vanguardnr.com If you reduce the window size, you'll notice a new menu item "More" is created and other menu items that can't fit in the navigation bar are placed as submenus on the "More" menu item. What I need to know is the logic.

Thanks

I think it's the work of bootstrap

Emmach10:
I think it's the work of bootstrap

Really? How? I don't think that done by Bootstrap

You want certain list items (li) to hide when the page width reduces beyond a value.
If you were to do it without a framework then it will likely involve:
1) knowing the li(s) you want to hide beforehand, 2) creating two copies of those li(s), placing one set of the li(s) directly, under the ul(unordered list) wrapper and the other under the "more" li.
3) Then finally you toggle the appearance of "more" li and the li(s) to be hidden.
Toggling is possible through Js or html radio button embbeded within the li(s).