JavaScript去掉alert 弹框中的URL

<script>
/*remove url of alert/confirm*/
var wAlert = window.alert;
window.alert = function(message) {
  try {
    var iframe = document.createElement("IFRAME");
    iframe.style.display = "none";
    iframe.style.color = "pink";
    iframe.style.fontSize = "240px";
    iframe.setAttribute("src", 'data:text/plain,');
    document.documentElement.appendChild(iframe);
    var alertFrame = window.frames[0];
    var iwindow = alertFrame.window;
    if (iwindow == undefined) {
      iwindow = alertFrame.contentWindow;
    }
    iwindow.alert(message);
    iframe.parentNode.removeChild(iframe);
  } catch (exc) {
    return wAlert(message);
  }
}
</script>