title: jQuery - use canvas to draw lines between divs
body: <p>I have n <code>&lt;div</code>>s, each with <code>&lt;h1</code>> title and <code>&lt;ul</code>> list of items in.</p>
  
  <p>I would like to float these over a canvas and draw lines from <code>&lt;div id="x"</code>> list item y to <code>&lt;div id="z"</code>>. I am using jQuery UI to make the <code>&lt;div</code>>s draggable.</p>
  
  <p>The canvas element is part way down the page (a paragraph of text and some form elements precede it) but I can change this if necessary.</p>
  
  <p>[edit]</p>
  
  <p>I tagged the question with graph, but let me add this link: <a href="http://en.wikipedia.org/wiki/Graph_%28mathematics%29" rel="noreferrer">Graph_(mathematics)</a> :-)</p>