function displayNewMark() {
 if(!document.getElementsByTagName) return;

 // passage time
 var passageTime = 72; 
 // display mark
 var mark = 'up';

 var currentDate = new Date();

 var elements = document.getElementsByTagName('span');
 for (var i = 0,len = elements.length; i < len; i++) {
  if(elements[i].className == 'new'){

  var time = elements[i].firstChild.nodeValue.split(':');
  var entryDate = new Date(time[0], time[1]-1, time[2], time[3], time[4], time[5]);
  var currentTime = (entryDate.getTime () -  currentDate.getTime())/(60*60*1000);
  currentTime = Math.ceil(currentTime);
  if(-currentTime <= passageTime){
      elements[i].innerHTML = mark;
      elements[i].style.display = 'inline';
     }
   }
  }
}