title: transparency on uiimageview should show image
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/629409/how-to-draw-a-transparent-stroke-or-anyway-clear-part-of-an-image-on-the-iphon">How to draw a transparent stroke (or anyway clear part of an image) on the iPhone</a>  </p>
  </blockquote>
  
  
  
  <p>I have a uiimage view on that a transparent layer is there
  if we make touch on that transparent layer that touched part transparent layer should be erased and should show the image back of it.. how can i do this....?
  thanks in advance</p>