html中iframe根据子页面内容动态修改高度

var browserVersion = window.navigator.userAgent.toUpperCase();
var isOpera = browserVersion.indexOf("OPERA") > -1 ? true : false;
var isFireFox = browserVersion.indexOf("FIREFOX") > -1 ? true : false;
var isChrome = browserVersion.indexOf("CHROME") > -1 ? true : false;
var isSafari = browserVersion.indexOf("SAFARI") > -1 ? true : false;
var isIE = (!!window.ActiveXObject || "ActiveXObject" in window);
var isIE9More = (! -[1, ] == false);

function reinitIframe(iframeId, minHeight) {
    try {
        var iframe = document.getElementById(iframeId);
        var bHeight = 0;
        if (isChrome == false && isSafari == false)
            bHeight = iframe.contentWindow.document.body.scrollHeight;

        var dHeight = 0;
        if (isFireFox == true)
            dHeight = iframe.contentWindow.document.documentElement.offsetHeight + 2;
        else if (isIE == false && isOpera == false)
            dHeight = iframe.contentWindow.document.documentElement.scrollHeight;
        else if (isIE == true && isIE9More) {//ie9+
            var heightDeviation = bHeight - eval("window.IE9MoreRealHeight" + iframeId);
            if (heightDeviation == 0) {
                bHeight += 3;
            } else if (heightDeviation != 3) {
                eval("window.IE9MoreRealHeight" + iframeId + "=" + bHeight);
                bHeight += 3;
            }
        }else//ie[6-8]、OPERA
            bHeight += 3;

        var height = Math.max(bHeight, dHeight);
        if (height < minHeight) height = minHeight;
        iframe.style.height = height + "px";

    } catch (ex) { }
}
function startInit(iframeId, minHeight) {
    eval("window.IE9MoreRealHeight" + iframeId + "=0");
    window.setInterval("reinitIframe(‘" + iframeId + "‘," + minHeight + ")", 100);
}
var minHeight = $(window).height();
startInit(‘contents‘, minHeight);