Can't catch callback with JavaScript Interface on IE9, IE10 and IE11


The following code was working on February 25 with Internet Explorer.
But now, it doesn’t work on IE9, IE10 and IE11. Would appreciate any assistance…
Thanks in advance.

<!DOCTYPE html>
    <script src="//" type="text/javascript"></script>
    <a id="shareLink" href="">Tweet</a>
    <script>'tweet', function (event) {
      var myurl = "";
      var mytext = "Text";
      var url = "" +
                "?url=" + encodeURIComponent(myurl) +
                "&text=" + encodeURIComponent(mytext);
      document.getElementById("shareLink").href = url;