function tab_delivery(type) {
    switch (type) {
        case "hanjin" :
            document.getElementById('delivery_hanjin').style.display="inline";
            document.getElementById('delivery_ems').style.display="none";
            $('delivery_tab').style.backgroundPosition="0px 0px";
            break;
        case "ems" :
            document.getElementById('delivery_hanjin').style.display="none";
            document.getElementById('delivery_ems').style.display="inline";
            $('delivery_tab').style.backgroundPosition="0px 345px";
            break;
    }

}