.button_buy {
    background:transparent url(/img/istay_submit.gif) no-repeat scroll 0 0;
    color:#FFFFFF;
    cursor:pointer;
    display:block;
    height:28px;
    line-height:28px;
    text-align:center;
    width:88px;
    margin-top:10px;
    }

.button_buy:hover {
    color:white;
    }