iframe子页面操作父页面并实现屏蔽页面弹出层效果

<style type="text/css">
#BgLayer {
background: #939393 none repeat scroll 0 0;
height:100%;
width:100%;
left:0;
top:0;
filter: alpha(opacity=80); /* IE */
-moz-opacity: 0.8; /* Moz + FF */
z-index: 10000;
}
#Layer {
width: 400px;
height: 400px;
margin: -180px 0 0 -170px;
left: 50%;
top: 50%;
position: absolute;
background: #FFF;
z-index: 10001;
border: 1px solid #1B5BAC;
}
</style>
<script type="text/javascript">
/*显示页面*/
function showDiv) {
var bg = document.getElementById("BgLayer");
var con = document.getElementById("Layer");
//var w = document.documentElement.clientWidth; //网页可见区域宽
//var h = document.documentElement.clientHeight;//网页可见区域高
var w = document.body.scrollWidth; //网页正文全文宽
var h = document.body.scrollHeight; //网页正文全文高
// alert(w+"-"+h);
bg.style.display = "";
bg.style.width = w + "px";
bg.style.height = h + "px";
con.style.display = "";
}
/*关闭*/
function closeDiv() {
var bg = document.getElementById("BgLayer");
var con = document.getElementById("Layer");
bg.style.display = "none";
con.style.display = "none";
}
</script>

四：son.html 中某个操作调用父页面方法