Hi there. I would love to create an advertising div that would be place vertically on the left of the screen when viewed on large displays, and then have it move to the top as a more traditional horizontal ad when viewed on a smaller monitor.
I suggest you look for boostrap framework. If you know some of the media query you can do it yourself, just make sure that you place your ads div at the top of other element. Use css float or position to set it for wide screen and small screen devices.