title: Check if div is viewable in window?
body: <p>I have a one page site with fixed navigation and using a scroll script, very similar to this: <a href="http://www.ivanjevremovic.in.rs/live/temptation/single/orange/index-cycle-slider.html">http://www.ivanjevremovic.in.rs/live/temptation/single/orange/index-cycle-slider.html</a></p>
  
  <p>What I'm looking for is a way to check what section is viewable in the window to set the active state on the nav when using the browsers scroll bar, any ideas?</p>