Menu stretched and does't fixed?!

Hi guys, consider the main menu (first menu) and in the main menu (second menu). what I have to do to make the main menu looks like the top menu, so that it is stretched to the bottom of the page, and as I do not go up the top menu when scrolling down the page?

image:
http://themezhut.com/wp-content/uploads/2014/12/Awaken-WordPress-Theme-Widget-Areas.jpg