function ImportJavaScript(sourceUrl)
{
  var scriptElem = document.createElement('script');
  scriptElem.src = sourceUrl;
  scriptElem.type = 'text/javascript';
  document.getElementsByTagName('head')[0].appendChild(scriptElem);
}

function ImportCss(sourceUrl)
{
  if(document.createStyleSheet)
    document.createStyleSheet(sourceUrl);
  else
  {
    var linkElem = document.createElement('link');
    linkElem.rel = 'stylesheet';
    linkElem.type = 'text/css';
    linkElem.href = sourceUrl;
    document.getElementsByTagName("head")[0].appendChild(linkElem);
  }
}

function set_theme() {
  var themes = new Array("green", "brown", "green", "turquoise", "green", "red", "green", "orange", "green", "purple");
  var currentTime = new Date();
  var minutes = currentTime.getMinutes()%10;
  ImportCss('/stylesheets/' + themes[minutes] + '.css')       
}