function file(fichier) {
      if (window.XMLHttpRequest)
          xhr_object = new XMLHttpRequest();
      else if (window.ActiveXObject)
          xhr_object = new ActiveXObject("Microsoft.XMLHTTP");

      else

          return (false);
      xhr_object.open("GET", fichier, false);
      xhr_object.send(null);
      if (xhr_object.readyState == 4)
          return (xhr_object.responseText);
      else
          return (false);

  }
  

  function loadNewDoc(doc) {
      $("#mainContainer").html(file(doc));
      return false

  }