var Browser = {
  a : navigator.userAgent.toLowerCase()
}

Browser = {
  ie : /*@cc_on true || @*/ false,
  ie6 : Browser.a.indexOf('msie 6') != -1,
  ie7 : Browser.a.indexOf('msie 7') != -1,
  opera : !!window.opera,
  safari : Browser.a.indexOf('safari') != -1,
  safari3 : Browser.a.indexOf('applewebkit/5') != -1,
  mac : Browser.a.indexOf('mac') != -1
}

function createElement(name, attrs, doc, xmlns) {
  var doc = doc || document;
  var elm;
  if(doc.createElementNS)
    elm = doc.createElementNS(xmlns || "http://www.w3.org/1999/xhtml", name);
  else
    elm = doc.createElement(name);
  if(attrs)
    for(attr in attrs)
      elm.setAttribute(attr, attrs[attr]);
  return elm;
}

function addStylesheet(href, media) {
  document.getElementsByTagName("head")[0].appendChild(
    createElement(
      'link',
      {
        'rel': 'stylesheet',
        'type': 'text/css',
        'media': media || 'screen, projection',
        'href': href
      }
    )
  );
}