var viewportwidth = 640;
var viewportheight = 480;
var screenW = screen.width;
var screenH = screen.height;

try {
    // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight 
    if (typeof window.innerWidth != 'undefined') {
        viewportwidth = window.innerWidth,
      viewportheight = window.innerHeight
    }
    // IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)  
    else if (typeof document.documentElement != 'undefined' && typeof document.documentElement.clientWidth != 'undefined' && document.documentElement.clientWidth != 0) {
        viewportwidth = document.documentElement.clientWidth,
       viewportheight = document.documentElement.clientHeight
    }
    // older versions of IE  
    else {
        viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
       viewportheight = document.getElementsByTagName('body')[0].clientHeight
    }
}
catch (ex) {
}

function iframeReSize() {
    // iframe auto reSize
    try {
        if (window != parent) {
            var a = parent.document.getElementsByTagName("iframe");
            for (var i = 0; i < a.length; i++) {
                if (a[i].contentWindow == window) {
                    var h = document.body.scrollHeight;
                    if (document.all) { h += 4; }
                    if (window.opera) { h += 1; }
                    a[i].style.height = h;
                }
            }
        }
    }
    catch (ex) {
        //alert("跨網域，禁止操作！");
    }
}