Div+Css+JS做弹出窗口

#divbg
{
width: 100%;
height: 100%;
position: absolute;
z-index: 999;
top: 0px;
left: 0px;
filter: alpha(opacity=50);
opacity: 0.5;
background-color: #AAAAAA;
}
#diveditcontent
{
width: 630px;
height: 150px;
position: absolute;
z-index: 1000;
background-color: #444444;
}
#divheader
{
width: 100%;
height: 25px;
background-color: #BB5500;
}

<div id="divbg" style="display: none;">
</div> //弹出窗口的背景(遮挡当前页)
<div id="diveditcontent" style="display: none;"> //窗口内容页
<div style="margin-right: 3px; margin-bottom: 3px; width: 99.7%">
<div id="divheader" title="Move>"> //窗口标题行
<div style="float: left; margin-top: 5px; margin-left: 3px;">
<strong>
Edit</strong></div>
<div style="float: right; margin-top: 5px; margin-right: 3px;">
<a href="#" onclick="Hide();" title="Close"><strong>X</strong></a></div> //关闭
</div>
<div id="divcontent"> //内容
</div>
</div>
</div>

<script type="text/javascript">
var divheader = document.getElementById("divheader");
var divbg = document.getElementById("divbg");
var diveditcontent = document.getElementById("diveditcontent");
var selects = document.getElementsByTagName("select");
var divcontent = document.getElementById("divcontent");
function Show(Key) {

divbg.style.display = "";
divbg.style.width = document.body.offsetWidth; //浏览器宽度(滚动条+clientwidth+边框）
divbg.style.height = document.body.offsetHeight;

diveditcontent.style.display = "";
diveditcontent.style.top = "50px"; //弹出窗口位置
diveditcontent.style.left = "100px";

for (var i = 0; i < selects.length; i++) {
selects[i].style.display = "none"; //遮住下拉框
}

divcontent.innerHTML = "<iframe frameborder=0 scrolling=no src='PriceEdit.aspx?Key=" + Key + "' width='100%' height='100%'></iframe>";
//嵌入页

}
function Hide() {
//隐藏窗口
document.location = location.reload();
divbg.style.display = "none";
diveditcontent.style.display = "none";

for (var i = 0; i < selects.length; i++) {
selects[i].style.display = "";
}

}
divheader.onmousedown = Down;
//以下是拉窗口自由移动
var th;
var tw;
function Down(e) {

var event = window.event || e;
th = event.clientY - parseInt(diveditcontent.style.top.replace(/px/, ""), 10);
tw = event.clientX - parseInt(diveditcontent.style.left.replace(/px/, ""), 10);
document.onmousemove = Move;
document.onmouseup = Up;
document.onmouseout = Up;
function Move(e) {

var event = window.event || e;
var top = event.clientY - th;
var left = event.clientX - tw;
top = top < 0 ? 0 : top;
top = top > document.body.offsetHeight - 220 ? document.body.offsetHeight - 220 : top;

left = left < 0 ? 0 : left;
left = left > document.body.offsetWidth - 630 ? document.body.offsetWidth - 630 : left;

diveditcontent.style.top = top + "px";
diveditcontent.style.left = left + "px";
}

function Up() {
document.onmousemove = null;
}
}