title: Changing the volume without a volume slider on an iphone
body: <p>I need your help. How should I proceed to change the sound volume in my app. I don't want to use a volume slider. Instead I have an UIImageView which is a volume knob, in which I rotate clockwise to increase, and anti clockwise to decrease the sound volume. The rotation is just an animation and I've already done that part.</p>
  
  <p>I need your help and advice on how to increase/decrease the volume. Thanks</p>