Js制作简单弹出层DIV在页面居中 中间显示遮罩的具体方法

这两天要用到正好练练手,比想象中碰到的问题要多,比如:
ie6背景透明 ie6居中显示 还有对js对象的理解
openID=显示按钮,conID=需要显示的div,closeID=关闭按钮
解决了:
1.可以遮挡ie6下的select元素 但是在ie6下div没有透明度
2.弹出的div可以一直在浏览器屏幕中间显示
问题:
1.目前不支持.class 只支持#id
2.需要显示的div需要自己设置css
3.在ie6下需要设置css
例如div {_position: absolute;_top: expression(documentElement.scrollTop + 340 + "px"); }
4.ie6下背景div没有透明度 这里我上网搜到的结果都不能解决 如果您有方法请给我留言


代码如下:

<!DOCTYPE HTML>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Js制作简单弹出层DIV在页面居中 中间显示 遮罩 方法</title>
<style type="text/css">
*{margin:0;padding:0;}
#bt{border: 2px solid #000;background-color: #ccc;cursor: pointer;padding: 2px 5px;}
/****订单弹出框*****/
.orderMsg{ position:fixed;_position: absolute;_top: expression(documentElement.scrollTop + 340 + "px"); background:#fff; border:1px solid #939395; width:500px; height:340px;top: 50%;left: 50%;margin: -200px 0 0 -250px; overflow:hidden; z-index:99999; font-size:14px; color:#000; display:none;}
.orderMsg dl{ overflow:hidden; padding:20px; margin:0;}
.orderMsg dl dt{ line-height:30px;}
.orderMsg dl dd{ line-height:25px; height:25px; padding-left:10px; margin:0;}
.orderMsg dl dd label{ padding-left:5px;}
.orderMsg dl dd.cBtn{ width:102px; height:28px; background:url(../images/member/chooseBtn.gif) no-repeat; margin-top:10px; padding:0;}
.orderMsg dl dd.cBtn a{ display:block; text-align:center;}
.orderMsg dl dd.cBtn a:link,.orderMsg dl dd.cBtn a:visited{ color:#000;}
.orderMsg dl dd.lBtn{ float:left; display:inline; margin-left:100px;}
.orderMsg dl dd.rBtn{ float:left; display:inline; margin-left:10px;}
</style>
</head>
<body>
<a id="bt">点击弹出div</a>
<div style="height:1000px;">
sdfdsf
<select>
<option>Volvo</option>
<option selected="selected">Saab</option>
<option>Mercedes</option>
<option>Audi</option>
</select>
</div>
<a id="bt">点击弹出div</a>
<div style="height:1000px;">
sdfdsf
<select>
<option>Volvo</option>
<option selected="selected">Saab</option>
<option>Mercedes</option>
<option>Audi</option>
</select>
</div>
<div id="orderMsg" class="orderMsg" style="display: none;">
<dl>
<dt>请您告知我们取消订单的原因，以便我们改进。非常感谢!</dt>
<dd><input type="radio" name="reason" id="reason1"><label for="reason1">改变主意,现在不想买了</label></dd>
<dd><input type="radio" name="reason" id="reason2"><label for="reason2">刚才信息填错了,要重新下单</label></dd>
<dd><input type="radio" name="reason" id="reason3"><label for="reason3">先取消,再更换或添加新商品</label></dd>
<dd><input type="radio" name="reason" id="reason4"><label for="reason4">网银,信用卡等支付有问题</label></dd>
<dd><input type="radio" name="reason" id="reason5"><label for="reason5">等待时间过长,不耐烦了</label></dd>
<dd><input type="radio" name="reason" id="reason6"><label for="reason6">商品价格较贵</label></dd>
<dd><input type="radio" name="reason" id="reason7"><label for="reason7">出现商品缺货情况</label></dd>
<dd><input type="radio" name="reason" id="reason8"><label for="reason8">其它的原因</label></dd>
<dd><input type="radio" disabled="disabled"><label>72小时到期自动取消(不可选)</label></dd>
<dd class="cBtn lBtn"><a href="#">选好了</a></dd><dd class="cBtn rBtn"><a href="#" onclick="" id="close">点击取消</a></dd>
</dl>
</div>
<script type="text/javascript">
/*
openID=显示按钮,conID=需要显示的div,closeID=关闭按钮
解决了:
1.可以遮挡ie6下的select元素 但是在ie6下div没有透明度
2.弹出的div可以一直在浏览器屏幕中间显示
问题:
1.目前不支持.class 只支持#id
2.需要显示的div需要自己设置css
3.在ie6下需要设置css
例如div {_position: absolute;_top: expression(documentElement.scrollTop + 340 + "px"); }
4.ie6下背景div没有透明度 这里我上网搜到的结果都不能解决 如果您有方法请给我留言
*/
var _CalF = { //便捷方法
$ : function(id){return document.getElementById(id)},
create : function(id){return document.createElement(id)},
append : function(id){return document.body.appendChild(id)},
remove : function(id){return document.body.removeChild(id)}
}
function popup(openID,conID,closeID){
this.onclick(openID,conID,closeID);
}
popup.prototype = {
cssStyle : "width:100%;position:absolute;left:0;top:0;filter:alpha(opacity = 50);opacity:0.5;border:0;overflow:auto;",
createShadowDiv : function(){ //背景遮罩
var shadowDiv = _CalF.create("div");
shadowDiv.id = "shadowDiv";
shadowDiv.style.cssText = this.cssStyle;
shadowDiv.style.height = document.body.scrollHeight + "px";
shadowDiv.style.backgroundColor = "#000"
shadowDiv.style.zindex = 100;
_CalF.append(shadowDiv);
},
createIframe : function(){ //iframe
var iframe = _CalF.create("iframe");
iframe.id = "shadowIframe";
iframe.style.cssText = this.cssStyle;
iframe.style.height = document.body.scrollHeight + "px";
iframe.style.zindex = 99;
_CalF.append(iframe);
},
removeDiv : function(){
_CalF.remove(_CalF.$("shadowDiv"));
_CalF.remove(_CalF.$("shadowIframe"));
},
onclick : function(openID,conID,closeID){
var that = this;
_CalF.$(openID).onclick = function(){
if(window.ActiveXObject){ //ie6
if(!window.XMLHttpRequest){
document.body.style.cssText = "_background-image: url(about:blank);_background-attachment: fixed;";
}
}
that.createIframe();
that.createShadowDiv();
_CalF.$(conID).style.display = "block";
}
document.getElementById(closeID).onclick = function(){
_CalF.$(conID).style.display = "none";
that.removeDiv();
}
}
}
var bt = new popup("bt","orderMsg","close");
</script>
</body>
</html>