.black_overlay{
display: none;
position: absolute;
top: 0%;
left: 0%;
width: 100%;
height: 1800px;
background-color: #8b8;
z-index:1001; 
-moz-opacity: 0.8;
opacity:.80;
filter: alpha(opacity=80);
} 
.white_content {
display: none;
position: absolute;
top: 25%;
left: 25%;
width: 40%;
height: 40%;
padding: 10px;
border: 2px solid orange;
background-color: white;
z-index:1002;
overflow: auto;
font-size:14px;
}