如何正确显示@ 2x视网膜图像

  I'm using Xcode 4.5.2, the app is targeting iOS 6.0. In my application, I am having trouble with showing iPad Retina images. I know I have to use the @2x~ipad.png extension in order to get them to properly show and I do that. My images are named according so they are all named the same besides the extension for each device. Here is how I named it.  I'm using Xcode 4.5.2, the app is targeting i