Css代码
++复制代码++ 代码如下:

#brg
{
width: 100%;
height: 100%;
background: #333;
position: absolute;
top: 0;
left: 0;
filter: alpha(opacity=60);
-moz-opacity: 0.6;
opacity: 0.6;
position: absolute;
top: 0;
left: 0;
display: none;
}
#showdiv
{
width: 100%;
height: auto;
position: absolute;
left: 300px;
top: 150px;
z-index: 330;
display: none;
}
#testdiv
{
width: 800px;
height: auto;
margin: 0 0;
border: 1px solid #4d4d4d;
background: #f2f2f2;
}
#close
{
width: 200px;
height: 27px;
line-height: 27px;
font-size: 14px;
font-weight: bold;
border: 1px solid #4d4d4d;
text-align: center;
cursor: pointer;
margin: 0 auto;
background: #333;
color: #fff;
}

Html 代码
++复制代码++ 代码如下:

<div id="brg">
</div>
<div id="showdiv">
<div id="close">
关闭
</div>
<div id="testdiv">

要显示的内容

</div>
</div>

Jquery 代码
++复制代码++ 代码如下:

$(document).ready(function() {
var bheight = document.body.clientHeight;
$("#btnAdd").click(function() {
$("#brg").css("display", "block");
$("#showdiv").css("display", "block");
$("#brg").css("height", document.body.scrollHeight);
$("#showdiv").css("top", document.body.scrollTop + 100);
});
$("#close").click(function() {
$("#brg").css("display", "none");
$("#showdiv").css("display", "none");
});
});