title: make a background image full screen in landscape iPhone
body: <p>I want to  make a background image full screen in landscape iPhone.In iPhone simulator,the image appeared,but isn't full screen.Here is my code</p>
  
  <pre><code>CGSize size=[[CCDirector sharedDirector] winSize];
  [self addChild:backgroundImage z:0 tag:0];
  NSLog(@"size.height %f,size.width %f,image.width %f,image.height %f",size.height,size.width,backgroundImage.contentSize.width,backgroundImage.contentSize.height);
  </code></pre>
  
  <p>Xcode output
  size.height 480.000000,size.width 320.000000,image.width 480.000000,image.height 320.000000
  And I know iPhone is 480*320 points.Why is the image not full screen?</p>