var loca=self.location.href;
var long_parametres
var parametres=loca.substring(loca.indexOf("?")+1,loca.length);
long_parametres=parametres.length;

function valParam(chPrc, chaine){
  chaine = chaine + "=";
  var pos_param;
  var chRetour = '';
  pos_param = chPrc.indexOf(chaine);
  if (pos_param>=0){
    chRetour = "Trouve";
    pos_param = pos_param + chaine.length;
    var fin_param = chPrc.indexOf("&",pos_param);
    if (fin_param<0) fin_param = chPrc.length;
    chRetour = chPrc.substring(pos_param,fin_param);
  } else {
    chRetour = "";
  }
  return chRetour;
}