【www.gdgbn.com--js教程】

$()和$c()分别表示
$(id)，获取该id的对象,document.getelementbyid(id)
$c(tag)，创建一个标签, document.createelement(tag);

//初始化导航背景，iframe容器

function fndaohangbg()
{
var h = fngetheight(),w = fngetwidth();//获取背景窗口大小
if(!$("divdaohangbg"))
{
var div = $c("div");//创建背景蒙板
div.id = "divdaohangbg";
div.style.backgroundcolor = "black";
div.style.position = "absolute";
div.style.filter = "alpha(opacity=80)";
div.style.opacity = ".80";
div.style.zindex = 100001;
div.style.left = 0;
div.style.top = 0;
div.style.width = w+"px";
div.style.height= h+"px";
document.body.appendchild(div);
}

if(!$("divdaohangbgiframe"))
{
var iframe;
iframe = this.$c("iframe");//创建蒙板内的内嵌iframe容器，用于嵌入显示其他网页
iframe.id = "divdaohangbgiframe";
iframe.frameborder = "0";
iframe.scrolling = "no";
iframe.style.overflow = "hidden";
iframe.allowtransparency = "true";
iframe.style.display = "none";
iframe.style.width = w+"px";//800
iframe.style.height = h+"px";//620
iframe.style.margintop = "75px";//800
$("divdaohangbg").appendchild(iframe);
}
if(!$("divdaohangbgclose"))
{
var div = $c("div");//创建关闭按钮在蒙板上
div.id = "divdaohangbgclose";
div.style.position = "absolute";
div.style.backgroundimage="url(images/closb.gif)";
div.style.zindex = 100003;
div.style.right = 10;
div.style.top = 20;
div.style.width = "82px";
div.style.height= "30px";
div.title="关闭";
div.style.cursor="hand";
div.onclick=function(){//点击时间 ，关闭蒙板
fndaohangbgclose();
};
$("divdaohangbg").appendchild(div);
}
$("divdaohangbgiframe").style.display="block";
$("divdaohangbg").style.display="block";
}
//关闭蒙板
function fndaohangbgclose()
{
if(!$("divdaohangbg")){return;}
if(!$("divdaohangbgiframe")){return;}
$("divdaohangbgiframe").src="";
$("divdaohangbgiframe").style.display="none";
$("divdaohangbg").style.display="none";
}
//调用，内嵌url
function fndaohangbgshow(url)
{
fndaohangbg();
$("divdaohangbgiframe").src=url;
}

总结
用于在现有窗口上加载蒙板，在蒙板内在嵌入其他页面内容

本文来源：http://www.gdgbn.com/wangyezhizuo/28039/