diff --git a/pretalx_broadcast_tools/static/pretalx_broadcast_tools/generic.js b/pretalx_broadcast_tools/static/pretalx_broadcast_tools/generic.js
index fa0eeba..b9190f1 100644
--- a/pretalx_broadcast_tools/static/pretalx_broadcast_tools/generic.js
+++ b/pretalx_broadcast_tools/static/pretalx_broadcast_tools/generic.js
@@ -1,5 +1,6 @@
 schedule = null;
 event_info = null;
+req = {};
 
 function get_current_talk(max_offset) {
     room_name = get_room_name();
@@ -88,27 +89,31 @@ function format_time_from_pretalx(from_pretalx) {
 }
 
 function xhr_get(url, callback_func) {
-    req = new XMLHttpRequest();
-    req.timeout = 10000;
-    req.open('GET', url);
-    req.setRequestHeader('Accept', 'application/json');
-    req.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
-    req.addEventListener('load', function(event) {
-        if (req.status != 200) {
-            return;
-        }
+    req[url] = new XMLHttpRequest();
+    req[url].timeout = 10000;
+    req[url].onreadystatechange = () => {
+        if (req[url].readyState === 4) {
+            if (req[url].status != 200) {
+                return;
+            }
 
-        callback_func(event);
-    });
-    req.send();
+            callback_func(req[url].responseText);
+        }
+    };
+    req[url].open('GET', url);
+    req[url].setRequestHeader('Accept', 'application/json');
+    req[url].setRequestHeader("Content-Type", "application/json;charset=UTF-8");
+    req[url].send();
 }
 
 function update_schedule() {
-    xhr_get('../event.json', function() {
-        event_info = JSON.parse(req.responseText);
+    xhr_get('../event.json', function(text) {
+        console.log("events: " + text);
+        event_info = JSON.parse(text);
     });
-    xhr_get('../schedule.json', function() {
-        data = JSON.parse(req.responseText);
+    xhr_get('../schedule.json', function(text) {
+        console.log("schedule: " + text);
+        data = JSON.parse(text);
         if ('error' in data) {
             console.error(data['error']);
         } else {
diff --git a/pretalx_broadcast_tools/static/pretalx_broadcast_tools/lower_thirds.js b/pretalx_broadcast_tools/static/pretalx_broadcast_tools/lower_thirds.js
index 40f2428..efe97f7 100644
--- a/pretalx_broadcast_tools/static/pretalx_broadcast_tools/lower_thirds.js
+++ b/pretalx_broadcast_tools/static/pretalx_broadcast_tools/lower_thirds.js
@@ -7,40 +7,40 @@ function update_lower_third() {
     }
 
     box = document.getElementById('broadcast_tools_lower_thirds_box');
-    title = document.getElementById('broadcast_tools_lower_thirds_title').innerHTML;
-    speaker = document.getElementById('broadcast_tools_lower_thirds_speaker').innerHTML;
-    infoline = document.getElementById('broadcast_tools_lower_thirds_infoline').innerHTML;
+    title = document.getElementById('broadcast_tools_lower_thirds_title');
+    speaker = document.getElementById('broadcast_tools_lower_thirds_speaker');
+    infoline = document.getElementById('broadcast_tools_lower_thirds_infoline');
 
-    box.style.backgroundColor = event_info['color']);
+    box.style.backgroundColor = event_info['color'];
 
     if (!schedule)  {
-        title = 'Waiting for schedule ...';
+        title.innerHTML = 'Waiting for schedule ...';
         return
     }
 
     if ('error' in schedule) {
-        title = 'Error';
-        speaker = schedule['error'].join('<br>');
-        infoline = '';
+        title.innerHTML = 'Error';
+        speaker.innerHTML = schedule['error'].join('<br>');
+        infoline.innerHTML = '';
         return
     }
 
     if (schedule['rooms'].length > 1 && !schedule['rooms'].includes(room_name)) {
-        title = 'Error';
-        speaker = 'Invalid room_name. Valid names: ' + schedule['rooms'].join(', ');
-        infoline = '';
+        title.innerHTML = 'Error';
+        speaker.innerHTML = 'Invalid room_name. Valid names: ' + schedule['rooms'].join(', ');
+        infoline.innerHTML = '';
         return
     }
 
     current_talk = get_current_talk(5);
     if (current_talk) {
-        title = current_talk['title'];
-        speaker = current_talk['persons'].join(', ');
-        infoline = current_talk['infoline'];
+        title.innerHTML = current_talk['title'];
+        speaker.innerHTML = current_talk['persons'].join(', ');
+        infoline.innerHTML = current_talk['infoline'];
     } else {
-        title = event_info['no_talk'];
-        speaker = '';
-        infoline = '';
+        title.innerHTML = event_info['no_talk'];
+        speaker.innerHTML = '';
+        infoline.innerHTML = '';
     }
 
     if (current_talk && current_talk['track']) {
diff --git a/pretalx_broadcast_tools/static/pretalx_broadcast_tools/room_info.js b/pretalx_broadcast_tools/static/pretalx_broadcast_tools/room_info.js
index 486d658..8edd925 100644
--- a/pretalx_broadcast_tools/static/pretalx_broadcast_tools/room_info.js
+++ b/pretalx_broadcast_tools/static/pretalx_broadcast_tools/room_info.js
@@ -7,36 +7,36 @@ function update_room_info() {
     }
 
     box = document.getElementById('broadcast_tools_room_info');
-    roomname = document.getElementById('broadcast_tools_room_info_roomname').innerHTML;
-    title = document.getElementById('broadcast_tools_room_info_title').innerHTML;
-    speaker = document.getElementById('broadcast_tools_room_info_speaker').innerHTML;
-    qr = document.getElementById('broadcast_tools_room_info_qr').innerHTML;
+    roomname = document.getElementById('broadcast_tools_room_info_roomname');
+    title = document.getElementById('broadcast_tools_room_info_title');
+    speaker = document.getElementById('broadcast_tools_room_info_speaker');
+    qr = document.getElementById('broadcast_tools_room_info_qr');
 
     if (!room_name) {
-        roomname = event_info['name'];
-        title = 'Backstage';
-        speaker = '';
-        qr = '';
+        roomname.innerHTML = event_info['name'];
+        title.innerHTML = 'Backstage';
+        speaker.innerHTML = '';
+        qr.innerHTML = '';
         box.style.backgroundColor = event_info['color'];
         return
     }
 
     if (!schedule)  {
-        speaker = 'Waiting for schedule ...';
+        speaker.innerHTML = 'Waiting for schedule ...';
         return
     }
 
     if ('error' in schedule) {
-        title = 'Error';
-        speaker = schedule['error'].join('<br>');
-        qr = '';
+        title.innerHTML = 'Error';
+        speaker.innerHTML = schedule['error'].join('<br>');
+        qr.innerHTML = '';
         return
     }
 
     if (schedule['rooms'].length > 1 && !schedule['rooms'].includes(room_name)) {
-        title = 'Error';
-        speaker = 'Invalid room_name. Valid names: ' + schedule['rooms'].join(', ');
-        qr = '';
+        title.innerHTML = 'Error';
+        speaker.innerHTML = 'Invalid room_name. Valid names: ' + schedule['rooms'].join(', ');
+        qr.innerHTML = '';
         return
     }
 
@@ -54,19 +54,19 @@ function update_room_info() {
             qr_info = '';
         }
 
-        roomname = room_name;
-        title = current_talk['title'];
-        speaker = current_talk['persons'].join(', ');
-        qr = qr_info;
+        roomname.innerHTML = room_name;
+        title.innerHTML = current_talk['title'];
+        speaker.innerHTML = current_talk['persons'].join(', ');
+        qr.innerHTML = qr_info;
     } else {
-        roomname = event_info['name'];
-        title = room_name;
-        qr = '';
+        roomname.innerHTML = event_info['name'];
+        title.innerHTML = room_name;
+        qr.innerHTML = '';
 
         if (next_talk && event_info['room-info']['show_next_talk']) {
-            speaker = format_time_from_pretalx(next_talk['start']) + ' ' + next_talk['title'];
+            speaker.innerHTML = format_time_from_pretalx(next_talk['start']) + ' ' + next_talk['title'];
         } else {
-            speaker = '';
+            speaker.innerHTML = '';
         }
     }