if (document.images)
    {
      preload_image_object = new Image();
      // set image url
      image_url = new Array();
      image_url[0] = "http://www.entrejuineetrenarde.org/css/img/btn_01_s.jpg";
      image_url[1] = "http://www.entrejuineetrenarde.org/css/img/btn_02_s.jpg";
      image_url[2] = "http://www.entrejuineetrenarde.org/css/img/btn_03_s.jpg";
      image_url[3] = "http://www.entrejuineetrenarde.org/css/img/btn_04_s.jpg";
      image_url[4] = "http://www.entrejuineetrenarde.org/css/img/btn_05_s.jpg";
      image_url[5] = "http://www.entrejuineetrenarde.org/css/img/btn_06_s.jpg";

       var i = 0;
       for(i=0; i<=5; i++) 
         preload_image_object.src = image_url[i];
    }