gistfile1.js

function publishHeight() {

    if (window.location.hash.length == 0) return;

    var frameId = getFrameId();

    if (frameId == '') return;

    var actualHeight = getBodyHeight();
    var currentHeight = getViewPortHeight();

    if  (Math.abs(actualHeight - currentHeight) > 15) {
        var hostUrl = window.location.hash.substring(1);

        hostUrl += "#";
        hostUrl += 'frameId=' + frameId;
        hostUrl += '&';
        hostUrl += 'height=' + actualHeight.toString();

        window.top.location = hostUrl;
    }
}

function getFrameId() {

    var qs = parseQueryString(window.location.href);
    var frameId = qs["frameId"];

    var hashIndex = frameId.indexOf('#');

    if (hashIndex > -1) {
        frameId = frameId.substring(0, hashIndex);
    }

    return frameId;

}

function getBodyHeight() {

    var height,
        scrollHeight,
        offsetHeight;

    if (document.height) {

        height = document.height;

    } else if (document.body) {

        if (document.body.scrollHeight) {
            height = scrollHeight = document.body.scrollHeight;
        }

        if (document.body.offsetHeight) {
            height = offsetHeight = document.body.offsetHeight;
        }

        if (scrollHeight && offsetHeight) {
            height = Math.max(scrollHeight, offsetHeight);
        }
    }

    return height;
}

function getViewPortHeight() {

    var height = 0;

    if (window.innerHeight) {
        height = window.innerHeight - 18;
    } else if ((document.documentElement) && (document.documentElement.clientHeight)) {
        height = document.documentElement.clientHeight;
    } else if ((document.body) && (document.body.clientHeight)) {
        height = document.body.clientHeight;
    }

    return height;

}

function parseQueryString(url) {

    url = new String(url);

    var queryStringValues = new Object(),
        querystring = url.substring((url.indexOf('?') + 1), url.length),
        querystringSplit = querystring.split('&');

    for (i = 0; i < querystringSplit.length; i++) {
        var pair = querystringSplit[i].split('='),
            name = pair[0],
            value = pair[1];

        queryStringValues[name] = value;
    }

    return queryStringValues;

}