diff --git a/html/website.html b/html/website.html
index 01b03bc..241895b 100644
--- a/html/website.html
+++ b/html/website.html
@@ -87,7 +87,7 @@
     </div>
     <div class="container my-5" id="rfidModTags">
         <h2>RFID-Modifkationen</h2>
-        <form class="needs-validation" action="#rfidModTags" method="POST" onsubmit="rfidMods('rfidModTags'); return false" novalidate>
+        <form class="needs-validation" action="#rfidModTags" method="POST" onsubmit="rfidMods('rfidModTags'); return false">
             <div class="form-group col-md-6">
                 <label for="rfidIdMod">RFID-Chip-Nummer</label>
                 <input type="text" class="form-control" id="rfidIdMod" maxlength="12" pattern="[0-9]{12}" placeholder="%RFID_TAG_ID%" name="rfidIdMod" required>
@@ -116,7 +116,7 @@
     </div>
     <div class="container my-5" id="mqttConfig">
         <h2>MQTT-Konfiguration</h2>
-        <form class="needs-validation" action="#mqttConfig" method="POST" onsubmit="mqttSettings('mqttConfig'); return false" novalidate>
+        <form class="needs-validation" action="#mqttConfig" method="POST" onsubmit="mqttSettings('mqttConfig'); return false">
             <div class="form-check col-md-6">
                 <input class="form-check-input" type="checkbox" value="1" id="mqttEnable" name="mqttEnable" %MQTT_ENABLE%>
                 <label class="form-check-label" for="mqttEnable">
@@ -178,25 +178,28 @@
           var errorBox = '<div class="alert alert-danger alert-dismissible fade show" role="alert">Es ist ein Fehler aufgetreten!<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button></div>';
           var okBox = '<div class="alert alert-success alert-dismissible fade show" role="alert">Aktion erfolgreich ausgeführt.<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button></div>';
 
-          (function() {
-            'use strict';
-            window.addEventListener('load', function() {
-              /* Fetch all the forms we want to apply custom Bootstrap validation styles to*/
-              var forms = document.getElementsByClassName('needs-validation');
-              /* Loop over them and prevent submission*/
-              var validation = Array.prototype.filter.call(forms, function(form) {
-                form.addEventListener('submit', function(event) {
-                  if (form.checkValidity() === false) {
-                    event.preventDefault();
-                    event.stopPropagation();
-                  }
-                  form.classList.add('was-validated');
-                }, false);
-              });
-            }, false);
-          });
+          var socket = new WebSocket("ws://%IPv4%/ws");
 
-          let socket = new WebSocket("ws://%IPv4%/ws");
+          function ping() {
+            var myObj = {
+              "ping": {
+                ping: 'ping'
+              }
+            };
+            var myJSON = JSON.stringify(myObj);
+            socket.send(myJSON);
+            tm = setTimeout(function () {
+              alert("Die Verbindung zum Tonuino ist unterbrochen!\\nBitte Seite neu laden.");
+              }, 5000);
+          }
+
+          function pong() {
+            clearTimeout(tm);
+          }
+
+          socket.onopen = function () {
+            setInterval(ping, 15000);
+          };
 
           socket.onclose = function(e) {
             console.log('Socket is closed. Reconnect will be attempted in 1 second.', e.reason);
@@ -207,7 +210,7 @@
 
           socket.onerror = function(err) {
             console.error('Socket encountered error: ', err.message, 'Closing socket');
-            ws.close();
+            socket.close();
           };
 
           socket.onmessage = function(event) {
@@ -225,6 +228,10 @@
               } else {
                 $("#" + lastIdclicked).find('.messages').html(errorBox);
               }
+            } if (socketMsg.pong != null) {
+              if (socketMsg.pong == 'pong') {
+                pong();
+              }
             }
           };
 
diff --git a/src/main.cpp b/src/main.cpp
index 367ae0f..8d0c6a9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -668,6 +668,14 @@ void callback(const char *topic, const byte *payload, uint32_t length) {
     }
     // Modify sleep-timer?
     else if (strcmp_P(topic, topicSleepTimerCmnd) == 0) {
+        if (playProperties.playMode == NO_PLAYLIST) {       // Don't allow sleep-modications if no playlist is active
+            loggerNl((char *) FPSTR(modificatorNotallowedWhenIdle), LOGLEVEL_INFO);
+            publishMqtt((char *) FPSTR(topicSleepState), 0, false);
+            #ifdef NEOPIXEL_ENABLE
+                showLedError = true;
+            #endif
+            return;
+        }
         if (strcmp(receivedString, "EOP") == 0) {
             playProperties.sleepAfterPlaylist = true;
             loggerNl((char *) FPSTR(sleepTimerEOP), LOGLEVEL_NOTICE);
@@ -2291,9 +2299,7 @@ void doRfidCardModifications(const uint32_t mod) {
                 #ifdef NEOPIXEL_ENABLE
                     ledBrightness = initialLedBrightness;
                 #endif
-                #ifdef MQTT_ENABLE
-                    publishMqtt((char *) FPSTR(topicSleepTimerState), "0", false);
-                #endif
+                loggerNl((char *) FPSTR(modificatorSleepd), LOGLEVEL_NOTICE);
             } else {
                 if (playProperties.currentTrackNumber + 5 > playProperties.numberOfTracks) {        // If currentTrack + 5 exceeds number of tracks in playlist, sleep after end of playlist
                     playProperties.sleepAfterPlaylist = true;
@@ -2666,6 +2672,8 @@ bool processJsonRequest(char *_serialJson) {
         if (sSsid.compareTo(_ssid) || sPwd.compareTo(_pwd)) {
             return false;
         }
+    } else if (doc.containsKey("ping")) {
+        sendWebsocketData(0, 20);
     }
 
     return true;
@@ -2684,6 +2692,8 @@ void sendWebsocketData(uint32_t client, uint8_t code) {
         object["status"] = "error";
     } else if (code == 10) {
         object["rfidId"] = currentRfidTagId;
+    } else if (code == 20) {
+        object["pong"] = "pong";
     }
     char jBuf[50];
     serializeJson(doc, jBuf, sizeof(jBuf) / sizeof(jBuf[0]));
@@ -2701,7 +2711,7 @@ void onWebsocketEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, Aw
     if (type == WS_EVT_CONNECT){
         //client connected
         Serial.printf("ws[%s][%u] connect\n", server->url(), client->id());
-        client->printf("Hello Client %u :)", client->id());
+        //client->printf("Hello Client %u :)", client->id());
         client->ping();
     } else if (type == WS_EVT_DISCONNECT) {
         //client disconnected
@@ -3006,7 +3016,6 @@ void setup() {
     encoder.clearCount();
     encoder.setCount(initVolume*2);         // Ganzes Raster ist immer +2, daher initiale Lautstärke mit 2 multiplizieren
 
-
     // Only enable MQTT if requested
     #ifdef MQTT_ENABLE
         if (enableMqtt) {
@@ -3020,7 +3029,7 @@ void setup() {
     lastTimeActiveTimestamp = millis();     // initial set after boot
 
     if (wifiManager() == WL_CONNECTED) {
-        // Websocket
+        // Websocket for Mgmt-Interface
         ws.onEvent(onWebsocketEvent);
         wServer.addHandler(&ws);
 
diff --git a/src/websiteMgmt.h b/src/websiteMgmt.h
index 9b6771e..dae92ec 100644
--- a/src/websiteMgmt.h
+++ b/src/websiteMgmt.h
@@ -87,7 +87,7 @@ static const char mgtWebsite[] PROGMEM = "<!DOCTYPE html>\
     </div>\
     <div class=\"container my-5\" id=\"rfidModTags\">\
         <h2>RFID-Modifkationen</h2>\
-        <form class=\"needs-validation\" action=\"#rfidModTags\" method=\"POST\" onsubmit=\"rfidMods('rfidModTags'); return false\" novalidate>\
+        <form class=\"needs-validation\" action=\"#rfidModTags\" method=\"POST\" onsubmit=\"rfidMods('rfidModTags'); return false\">\
             <div class=\"form-group col-md-6\">\
                 <label for=\"rfidIdMod\">RFID-Chip-Nummer</label>\
                 <input type=\"text\" class=\"form-control\" id=\"rfidIdMod\" maxlength=\"12\" pattern=\"[0-9]{12}\" placeholder=\"%RFID_TAG_ID%\" name=\"rfidIdMod\" required>\
@@ -116,7 +116,7 @@ static const char mgtWebsite[] PROGMEM = "<!DOCTYPE html>\
     </div>\
     <div class=\"container my-5\" id=\"mqttConfig\">\
         <h2>MQTT-Konfiguration</h2>\
-        <form class=\"needs-validation\" action=\"#mqttConfig\" method=\"POST\" onsubmit=\"mqttSettings('mqttConfig'); return false\" novalidate>\
+        <form class=\"needs-validation\" action=\"#mqttConfig\" method=\"POST\" onsubmit=\"mqttSettings('mqttConfig'); return false\">\
             <div class=\"form-check col-md-6\">\
                 <input class=\"form-check-input\" type=\"checkbox\" value=\"1\" id=\"mqttEnable\" name=\"mqttEnable\" %MQTT_ENABLE%>\
                 <label class=\"form-check-label\" for=\"mqttEnable\">\
@@ -178,25 +178,28 @@ static const char mgtWebsite[] PROGMEM = "<!DOCTYPE html>\
           var errorBox = '<div class=\"alert alert-danger alert-dismissible fade show\" role=\"alert\">Es ist ein Fehler aufgetreten!<button type=\"button\" class=\"close\" data-dismiss=\"alert\" aria-label=\"Close\"><span aria-hidden=\"true\">&times;</span></button></div>';\
           var okBox = '<div class=\"alert alert-success alert-dismissible fade show\" role=\"alert\">Aktion erfolgreich ausgeführt.<button type=\"button\" class=\"close\" data-dismiss=\"alert\" aria-label=\"Close\"><span aria-hidden=\"true\">&times;</span></button></div>';\
 \
-          (function() {\
-            'use strict';\
-            window.addEventListener('load', function() {\
-              /* Fetch all the forms we want to apply custom Bootstrap validation styles to*/\
-              var forms = document.getElementsByClassName('needs-validation');\
-              /* Loop over them and prevent submission*/\
-              var validation = Array.prototype.filter.call(forms, function(form) {\
-                form.addEventListener('submit', function(event) {\
-                  if (form.checkValidity() === false) {\
-                    event.preventDefault();\
-                    event.stopPropagation();\
-                  }\
-                  form.classList.add('was-validated');\
-                }, false);\
-              });\
-            }, false);\
-          });\
+          var socket = new WebSocket(\"ws://%IPv4%/ws\");\
 \
-          let socket = new WebSocket(\"ws://%IPv4%/ws\");\
+          function ping() {\
+            var myObj = {\
+              \"ping\": {\
+                ping: 'ping'\
+              }\
+            };\
+            var myJSON = JSON.stringify(myObj);\
+            socket.send(myJSON);\
+            tm = setTimeout(function () {\
+              alert(\"Die Verbindung zum Tonuino ist unterbrochen!\\nBitte Seite neu laden.\");\
+              }, 5000);\
+          }\
+\
+          function pong() {\
+            clearTimeout(tm);\
+          }\
+\
+          socket.onopen = function () {\
+            setInterval(ping, 15000);\
+          };\
 \
           socket.onclose = function(e) {\
             console.log('Socket is closed. Reconnect will be attempted in 1 second.', e.reason);\
@@ -207,7 +210,7 @@ static const char mgtWebsite[] PROGMEM = "<!DOCTYPE html>\
 \
           socket.onerror = function(err) {\
             console.error('Socket encountered error: ', err.message, 'Closing socket');\
-            ws.close();\
+            socket.close();\
           };\
 \
           socket.onmessage = function(event) {\
@@ -225,6 +228,10 @@ static const char mgtWebsite[] PROGMEM = "<!DOCTYPE html>\
               } else {\
                 $(\"#\" + lastIdclicked).find('.messages').html(errorBox);\
               }\
+            } if (socketMsg.pong != null) {\
+              if (socketMsg.pong == 'pong') {\
+                pong();\
+              }\
             }\
           };\
 \