https://www.vergabeportal.at/assets/js/ie11.js

1(function (window) {
2    try {
3        new MouseEvent('test');
4        return false; // No need to polyfill
5    } catch (e) {
6        // Need to polyfill - fall through
7    }
8
9    // Polyfills DOM4 MouseEvent
10
11    var MouseEvent = function (eventType, params) {
12        params = params || { bubbles: false, cancelable: false };
13        var mouseEvent = document.createEvent('MouseEvent');
14        mouseEvent.initMouseEvent(eventType, params.bubbles, params.cancelable, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
15
16        return mouseEvent;
17    }
18
19    MouseEvent.prototype = Event.prototype;
20
21    window.MouseEvent = MouseEvent;
22})(window);