Simple iFrame Popup Window

<style type="text/css">
.popup {
        position:fixed;
        clear:both;
        height: 400px;
        width: 600px;
        z-index: 2;
        border: solid;
        background-color: white;
}
.grayBG {
        position: fixed;
        clear:both;
        top: 0px;
        left: 0px;
        right: 0px;
        bottom: 0px;
        overflow: hidden;
        padding: 0;
        margin: 0;
        background-color: #000;
        z-index: 1;
        filter:alpha(opacity=70);
        opacity:0.7;
        -moz-opacity:0.7;
}
</style>

<script language="javascript" type="text/javascript">
    function showDiv(id)
    {
        var div = document.getElementById("divPop");
        div.style.display = "block";
        var divFrame = document.getElementById("divFrame");
        divFrame.src = "PopupPage.aspx?id=" + id;        
        //document.body.style.scrolling = "no";
    }
    function hideDiv()
    {
        var div = document.getElementById("divPop");
        div.style.display = "none";
        //document.body.style.scrolling = "auto";
    } 
</script>

<div id="divPop" style="display: none;">
 <div class="grayBG" runat="server"></div>
 <div runat="server" class="popup">
    <a onclick="hideDiv();"></a><br />
    <iframe id="divFrame" runat="server" width="100%" height="100%">
    </iframe>
 </div>
</div>