gistfile1.js

    window.CurebitIntegration = {};

    (function() {
      CurebitIntegration.receiveMessage = function(callback) {
        if (window.addEventListener) {
          window.addEventListener("message", callback);
        } else {
          window.attachEvent("onmessage", callback)
        }
      };
    })();

    var curebitOfferDomain = "http://curebit.com",
        curebitOfferSrc    = curebitOfferDomain + "/o/dideeF/show/#" + encodeURIComponent(document.location.href),
        curebitOfferIframe = document.createElement("iframe");

    curebitOfferIframe.setAttribute("src", curebitOfferSrc);
    curebitOfferIframe.setAttribute("frameborder", "0");
    curebitOfferIframe.setAttribute("style", "display: block; height: 100%; left: 0; position: absolute; position: fixed; top: 0; width: 100%; z-index: 99999;");
    document.body.appendChild(curebitOfferIframe);

    CurebitIntegration.receiveMessage(function(e) {
      if (e.data === "curebit_close_offer_popup") {
        curebitOfferIframe.parentNode.removeChild(curebitOfferIframe);
      }
      console.log(e);
    });