$(document).ready(function(){
var btn_eng = '#banner_srv_soft_dev,'+
              '#banner_srv_net,' +
              '#banner_srv_soft_int,' +
              '#banner_srv_bus_an,' +
              '#banner_srv_proj_man,' +
              '#content_left_about,' +
              '#content_left_portfolio,' +
              '#content_left_partners,' +
              '#content_left_contact';

var btn_fr = '#banner_srv_soft_dev_fr,'+
             '#banner_srv_net_fr,' +
             '#banner_srv_soft_int_fr,' +
             '#banner_srv_bus_an_fr,' +
             '#banner_srv_proj_man_fr,' +
             '#content_left_about_fr,' +
             '#content_left_portfolio_fr,' +
             '#content_left_partners_fr,' +
             '#content_left_contact_fr';


$(btn_eng+','+btn_fr).append('<span class="hover"></span>').each(function () {
            var $span = $('> span.hover', this).css('opacity', 0);
            $(this).hover(function () {
            $span.stop().fadeTo(500, 1);
            }, function () {
                    $span.stop().fadeTo(500, 0);
            });
         });
});