function getUID(){
  var time1 = (new Date()).getTime();
  return "uid="+time1;
}

function getUIDAmped(){
  var time1 = (new Date()).getTime();
  return "&uid="+time1;
}

function uidfyurl(url){
  var uid = getUID();
  if(url.indexOf('?')==-1) url = url + '?'+uid;
  else url = url + '&'+uid;
  return url;
}

function loadscreen(url){
  $('screen').destroy();
  var screen = new Element('div', {id: 'screen'});
  $('main').grab(screen);

  url=uidfyurl(url);
  $('screen').load(url);
}

function screenloader(url){ 
  url = uidfyurl(url);
  var myRequest = new Request.HTML({
    onComplete: function(responseTree, responseElements, responseHTML, responseJavaScript){
      $('screen').set('html',responseHTML);
    }
  }).post(url);
}