function pay_ov(el)
{
    var src = el.id;
    src = src.substring(4, src.length);
    el.src = "/img/payments/" + src + "Over.png";
}
function pay_ou(el)
{
    var src = el.id;
    src = src.substring(4, src.length);
    el.src = "/img/payments/" + src + ".png";
}