title: How to draw an interactive image in PHP?
body: <p>I know how to draw rectangles in PHP (with GD), but how do we make them interactive ? I mean, is there a way to be notified when and where the user clicks ?</p>
  
  <p>Eventually, I would like to enable the user to select a rectangle among a set by clicking on it, and clicking anywhere else to move it. </p>
  
  <p>Thanks aforehand.</p>
  
  <p>Regards,</p>
  
  <p>Mister Mystère.</p>