function ecrire_cookie(nom, valeur, expires) {
  document.cookie=nom+"="+escape(valeur)+
  ((expires==null) ? "" : ("; expires="+expires.toGMTString()))+"; path=/";
}

function arguments_cookie(offset){
  var endstr=document.cookie.indexOf (";", offset);
  if (endstr==-1) endstr=document.cookie.length;
  return unescape(document.cookie.substring(offset, endstr)); 
}

function lire_cookie(nom) {
  var arg=nom+"=";
  var alen=arg.length;
  var clen=document.cookie.length;
  var i=0;
  while (i<clen){
    var j=i+alen;
    if (document.cookie.substring(i, j)==arg)
       return arguments_cookies(j);
    i=document.cookie.indexOf(" ",i)+1;
    if (i==0) break;
  }
  return null; 
}

function read_info(id) {
	// Date expiration 6 mois
	var todayDate = new Date();
	var dateExp = new Date();
	
	dateExp.setTime(todayDate.getTime() + 31*24*60*60*1000*6);
	
	// Ecriture du cookie
	ecrire_cookie('info'+id, 'read', dateExp);
	
	// Masque le cadre d'information
	var targetElement;
	targetElement = document.getElementById('infoBox') ;
	targetElement.style.display = "none" ;
}