实现半透明效果

1)<style type="text/css">

.modalBackground

{

background-color:Gray;

filter: alpha(opacity=50);

opacity: 0.5;

}

</style>

2)

<div id="mask" class="modalBackground" style=" position:absolute; left:0; top:0; display:none; width:100%; height:600px; z-index:100">

<iframe style="Z-INDEX:-1;WIDTH:100%;POSITION:absolute;HEIGHT:100%">

</iframe>

<table id ="imgTable" runat="server" style=" width:100%; height:100%;">

<tr><td align="center" valign="middle"><asp:Image ID="Image1" runat="server" ImageUrl="http://images.cnblogs.com/pleasewait.gif" /></td></tr>

</table>

</div>

<input type="button" id="btnSave" name="btnSave" value="保存" style="cursor:hand;" class="wind_btn" onclick="var mask =document.getElementById('mask');mask.style.display='block';setTimeout('SavePersonInfo()',1000)" />