// Author: David Kaspar
// You maywant to limit the script only to the sites that are causing showModalDialog problems
// ==UserScript==
// @name showModalDialogPatch
// @description Implement show modal dialog in Firefox
// @include	*
// ==/UserScript==
var unsafeWindow = window.unsafeWindow || window;
unsafeWindow.showModalDialog = function() {
            return unsafeWindow.confirm("Are you sure?");
}