用div层来实现页面半透明遮罩效果

<mce:script language="javascript"><!--

function Open()
{
//隐藏select控件
DispalySelect(0);
//显示遮罩层
document.getElementById("divPageMask").style.display="block";
//处理遮罩层
resizeMask();
window.onResize = resizeMask;
//显示弹出窗口
document.getElementById("divOpenWin").style.display="block";
}
function Close()
{
//显示select控件
DispalySelect(1);
//处理遮罩层
divPageMask.style.width = "0px";
divPageMask.style.height = "0px";
divOpenWin.style.display = "none";
window.onResize = null;

document.getElementById("divOpenWin").style.display="none";
}
//页面遮罩
function resizeMask()
{
divPageMask.style.width = document.body.scrollWidth;
divPageMask.style.height = document.body.scrollHeight;
divOpenWin.style.left = ((document.body.offsetWidth - divOpenWin.offsetWidth) / 2);
divOpenWin.style.top = ((document.body.offsetHeight - divOpenWin.offsetHeight) / 2);
}
function DispalySelect(val)
{  //显示和隐藏select控件
var dispalyType;
var arrdispalyType=["hidden","visible"];
var arrObjSelect=document.getElementsByTagName("select");
for (i=0;i<arrObjSelect.length;i++)
{
arrObjSelect[i].style.visibility=arrdispalyType[val];
}
}
// --></mce:script>

<mce:style type="text/css"><!--

.body,td{font-size:12px}
#divPageMask{background-color:white; filter:alpha(opacity=50);left:0px;position:absolute;top:0px;}
#divOpenWin{background-color:#EEEEEE;position: absolute;left:0px;top:0px;display: none;z-index:50; width:300px;height:150px}
--></mce:style><style type="text/css" mce_bogus="1">
.body,td{font-size:12px}
#divPageMask{background-color:white; filter:alpha(opacity=50);left:0px;position:absolute;top:0px;}
#divOpenWin{background-color:#EEEEEE;position: absolute;left:0px;top:0px;display: none;z-index:50; width:300px;height:150px}  </style>

<div id="divPageMask"></div>
<div id="divOpenWin"><center><a href="javascript:Close();" mce_href="javascript:Close();">关闭</a></center></div>
<label></label>
<center>
<table border="0" cellpadding="0" cellspacing="0" width="650">
<tbody>
<tr>
<td colspan="2" align="center" height="90"><p><img src="http://www.sopull.com/Images/Index/logo.gif" mce_src="http://www.sopull.com/Images/Index/logo.gif" height="60" width="250"></p>
<p> </p>
<p> </p></td>
</tr>
<tr>
<td height="10" style="color:#666666;font-size:13px" mce_style="color:#666666;font-size:13px"> </td>
</tr>
</tbody>
</table>
<table bgcolor="#e1e1e1" border="0" cellpadding="0" cellspacing="1" height="85" width="650">
<tbody>
<tr>
<td align="center" bgcolor="#f9f9f9"><table height=50 cellspacing=0 cellpadding=0 width=600 style="margin-top:20px" mce_style="margin-top:20px">
<FORM name="f" action="http://www.sopull.com/ShopList.asp">
<tbody>
<tr>
<td class="searchbar_word">关键字：</td>
<td width="241"><input type="text" name="k" size=30 /></td>
<td align=middle width=101 class="searchbar_word">所在地：</td>
<td align=middle width=97 id="cn"><mce:script language="javascript" src="http://www.sopull.com/Inc/Js/ListCity.asp?CityName=北京市" mce_src="http://www.sopull.com/Inc/Js/ListCity.asp?CityName=北京市"></mce:script></td>
<td align=middle width=95><input name="s" type=submit value=" 搜 铺 "></td>
</tr>
</form>
<tr>
<td width="64" height="30"> </td>
<td colspan="4" valign="middle" class="search_text">例如：餐厅；电器；超市
</table></td>
</tr>
</tbody>
</table>
</center>
<p align="center"> </p>
<p align="center"><a href="javascript:Open();" mce_href="javascript:Open();">打开遮罩</a></p>
<p align="center"> </p>
<table width="650" border="0" align="center" cellpadding="0" cellspacing="0">
<tbody>
<!--   <tr>
<td align="center" background="Images/Index/line_2.gif" width="580"><img src="Images/Index/line_2.gif" mce_src="Images/Index/line_2.gif" height="9" width="9"></td>
</tr>-->
<tr>
<td class="link" align="center" height="30"><a href="#" mce_href="#" target=_blank><font color="#FF6600">免费提交店铺</font></a> |  <a class="toplink" href="#" mce_href="#">店铺推广</a> |  <a class="toplink" href="#" mce_href="#">关于搜铺</a> |  <a class=b href="#" mce_href="#" target=_blank>业务合作</a>  |  <a class="toplink" onClick="this.style.behavior='url(#default#homepage)';this.setHomePage('http://www.sopull.com');return false;" href="http://www.sopull.com/#" mce_href="http://www.sopull.com/">设为首页</a> |  <a class="toplink" onClick="javascript:window.external.addFavorite('http://www.sopull.com/','搜铺网-中国最大店铺搜索引擎')" href="http://www.sopull.com/#" mce_href="http://www.sopull.com/">加入收藏</a> </td>
</tr>
<tr>
<td align="center" height="30">©2007 搜铺网     粤ICP备07006767号</td>
</tr>
</tbody>
</table>