function findSourceIframe(windowObj)
{
    var iframes = window.document.querySelectorAll('iframe');

    for(var i = 0; i < iframes.length; ++i) {
        if(windowObj === iframes[i].contentWindow) {
            return iframes[i];
        }
    }

    return null;
}


function receiveMessage(e)
{
    var _widthCorrection = (typeof widthCorrection == 'undefined' ? 0 : widthCorrection);
    var _heightCorrection = (typeof heightCorrection == 'undefined' ? 0 : heightCorrection);

    var origin = e.origin || e.originalEvent.origin;
    if (typeof allowedOrigin !== 'undefined' && origin !== allowedOrigin)
        return;

    var iframe = findSourceIframe(e.source.window);

    if(iframe) {
        iframe.style.height = (e.data.contentHeight + _heightCorrection) + 'px';
        iframe.style.width = (e.data.contentWidth + _widthCorrection) + 'px';
    }
}

window.addEventListener('message', receiveMessage, false);