window.addEvent('domready',function() {
  // Make png's transparent
  $$('img[src$=.png]').each(function(png) {
    png.setStyle('behavior','url(/_include/pngfix.htc)');
  });
  // External links open in new window
  $$('a[rel=external]').each(function(extLink) {
    extLink.setProperty('target','_blank');
  });
});