.pop_overlay{
width: 100%;
height: 100%;
background: #c2c2c2;
opacity: 0.5;
filter:alpha(opacity=50);
position: fixed;
z-index: 1;
left: 0;
top:0;
display: none;
}
.pop_con{
width: 534px;
height: 400px;
z-index: 2;
background: #ffffff;
position: absolute;
top:95%;
left: 50%;
margin-left: -267px;
display: none;
}
原文地址:http://www.cnblogs.com/xiaotaiyang/p/3907456.html