<div class="xiaotu" style="background:url(图片)">
<span>文字介绍</span>
</div>
.xiaotu {position:relative;top:0px;left:0px;float:left; 375px;height: 250px;z-index: 1;background-color:#030;}
.xiaotu a,.xiaotu span{display:none; text-decoration:none}
.xiaotu:hover{cursor:pointer;text-decoration:none}
.xiaotu:hover a.now{cursor:pointer; position:relative; top:0; 100%; height:100%;
z-index:100; left:0; display:block;}
.xiaotu:hover span{ display:block;position:relative; top:125px; left:5px;color:#FFF;365px;
z-index:10;height:120px; line-height:30px; background:#000;filter:alpha(opacity=60);-moz-opacity:0.5;opacity: 0.5;}