I'm using Bootstrap 3 and want to achieve this effect when the user scrolls past the large header image on my page. I need the background of the navbar to go from transparent to white. I looked in their code and I KNOW it is done with javascript, and even saw WHERE it was happening I think (look for the ID '#main-header' in that JS)...

Not knowing advanced Javascript aside, I'm looking for a way to apply this to my navigation bar when scrolling past a certain point. The class for my code is called 'navbar' and I would like it to turn white when it passes #main. Let me know if you need more information, and thanks in advance if anyone wants to help!