<input type="submit" value="Take Screenshot Of Div" onclick="capture();" />
<form>
  <input type="hidden" name="img_val" id="img_val" value="" />
</form>


<% content_for :foot do %>
 <script type="text/javascript" src="js/html2canvas.js"></script>


  <script>
    function capture() {
        html2canvas( [ document.body ], {
          onrendered: function(canvas) {
            document.body.appendChild(canvas);
          }
        });
    }
  </script>
<% end %>