title: Changing images depending on device orientation
body: <p>I'm building a basic web App using PhoneGap for a local company. I have created two images for the header/banner at the top of the App. One is optimised for portrait orientation and one is optimised for landscape.
  I want to be able to show either one depending which way the device is held. I have been reading about media queries and frankly its a little bit over complicated for my needs, as JQuery mobile will take care of rest of the functionality for me, and I'm only using one CSS for the whole App.</p>
  
  <p>Does anyone have a few simple lines of code I can add to help solve this issue?</p>