function init() {       
  Element.hide($('xdot'));
  var canviz;
  var xdot = $('xdot').innerHTML.unescapeHTML();
  /*
  var match = xdot.match(/bb=\"[0-9]+,[0-9]+,([0-9]+),([0-9]+)\"/);
  var width  = match[1];
  var height = match[2];
  var ret = Element.getDimensions($('scrollable'));
  var w = (ret.width) / width;
  var h = (ret.height) / height;
  var x = (w < h)? w : h
  */
  canviz = new Canviz('graph_container');
  var scale = 1
  canviz.setScale(scale);
  canviz.parse(xdot);
  Element.observe($('larger'), 'click', function(){
    scale *= 1.3;
    canviz.setScale(scale);
    canviz.draw();
  });
  Element.observe($('original'), 'click', function(){
    scale = 1;
    canviz.setScale(scale);
    canviz.draw();
  });
  Element.observe($('smaller'), 'click', function(){
    scale *= 0.7;
    canviz.setScale(scale);
    canviz.draw();
  });
}