.nav li dl {
    display:none;
    text-align:center;
    background:url(dfiles/9738/jwc/images/nav_bj.jpg) no-repeat;
    background-size: 100% 100%;
    color:#fff;
    z-index:999;
    position:relative;}
.nav li dl a {
    display:block;}

.nav li:hover dl {
    display:block;}