diff --git a/bengelsystem_konfiguration.php.template b/bengelsystem_konfiguration.php.template
index 1492318..c079e92 100644
--- a/bengelsystem_konfiguration.php.template
+++ b/bengelsystem_konfiguration.php.template
@@ -10,6 +10,8 @@ define('INFORMATIONS_URL', "https://meine-tolle-jonglierconvention.de");
 define('SECRET_KEY', "irgendwasZufaelliges"); // emails, see below
 define('SECRET_VERIFICATION', "irgendwasanderes,egalwas"); // emails, see below
 define('URLPREFIX', "https://https://meine-tolle-jonglierconvention.de/Bengelsystem/"); // our servername
+// local copy of jquery
+define('JQUERY', 'js/jquery-3.7.1.min.js');
 
 define('TAGE_DAUER', 4);
 
diff --git a/html/AdminAlleSchichten.php b/html/AdminAlleSchichten.php
index 31da008..07522d5 100644
--- a/html/AdminAlleSchichten.php
+++ b/html/AdminAlleSchichten.php
@@ -20,7 +20,7 @@ if ($AdminStatus != 1) {
   <link rel="stylesheet" href="css/style_mobile.css" media="screen and (max-width:780px)"/>
   <meta name="viewport" content="width=480" />
 
-  <script src="js/jquery-3.7.1.min.js" type="text/javascript"></script>
+  <script src="<?php echo JQUERY ?>" type="text/javascript"></script>
   <script src="js/helferdb.js" type="text/javascript"></script>
   <script> collapse_table_rows();
  </script>
diff --git a/html/AdminDienste.php b/html/AdminDienste.php
index d917fd3..e2f428a 100644
--- a/html/AdminDienste.php
+++ b/html/AdminDienste.php
@@ -28,10 +28,9 @@ if ($AdminStatus != 1) {
 
 
 DatenbankAufDeutsch($db_link);
-
-$DienstID = $_SESSION["DienstID"];
+isset($_SESSION["DienstID"]) && $DienstID = $_SESSION["DienstID"];
 $NewDienstID = 0;
-$SchichtID = $_SESSION["SchichtID"];
+isset($_SESSION["SchichtID"]) && $SchichtID = $_SESSION["SchichtID"];
 
 
 $HelferID = $_SESSION["HelferID"];
@@ -172,8 +171,9 @@ $Gruppe = "";
 $HelferLevel = "";
 
 while ($zeile = mysqli_fetch_array($db_erg, MYSQLI_ASSOC)) {
-    if ($zeile['DienstID'] != $DienstID) {
+    if (isset ($DienstID) && $zeile['DienstID'] != $DienstID) {
         echo "<option value='" . $zeile['DienstID'] . "'>" . $zeile['Was'] . "</option>";
+        $selectedset = true ;
     } else {
         echo "<option value='" . $zeile['DienstID'] . "' selected='selected'>" . $zeile['Was'] . "</option>";
 
@@ -185,6 +185,9 @@ while ($zeile = mysqli_fetch_array($db_erg, MYSQLI_ASSOC)) {
         $HelferLevel = $zeile['HelferLevel'];
     }
 }
+if( ! $selectedset ) { 
+echo "<option value='none' selected='selected'>Bitte auswählen</option>";
+}
 
 echo "</select>";
 echo "</th></tr>";
diff --git a/html/AdminHelferUebersicht.php b/html/AdminHelferUebersicht.php
index ca40d0a..9555b76 100644
--- a/html/AdminHelferUebersicht.php
+++ b/html/AdminHelferUebersicht.php
@@ -21,7 +21,7 @@ if ($AdminStatus != 1) {
   <link rel="stylesheet" href="css/style_desktop.css" media="screen and (min-width:781px)"/>
   <link rel="stylesheet" href="css/style_mobile.css" media="screen and (max-width:780px)"/>
   <meta name="viewport" content="width=480" />
-  <script src="js/jquery-3.7.1.min.js" type="text/javascript"></script> 
+  <script src="<?php echo JQUERY ?>" type="text/javascript"></script>
   <script src="js/helferdb.js" type="text/javascript"></script> 
   <script>
    collapse_table_rows();
diff --git a/html/AdminUserdaten.php b/html/AdminUserdaten.php
index 7a9055b..8f101cb 100644
--- a/html/AdminUserdaten.php
+++ b/html/AdminUserdaten.php
@@ -21,8 +21,13 @@ function HelferAuswahlButton($db_link, $AliasHelferID)
                 echo "<option value='" . $zeile['HelferID'] . "'>" . $zeile['Name'] . "</optionen>";
         } else {
                 echo "<option value='" . $zeile['HelferID'] . "' selected='selected'>" . $zeile['Name'] . "</optionen>";
+        $selectedSet = true;
         }
     }
+    if( !$selectedSet ) {
+      echo "<option value='none' selected='selected'>Bitte auswählen</optionen>";
+    }
+
     echo '</select></form>';
 }
 
diff --git a/html/AlleSchichten.php b/html/AlleSchichten.php
index 862d425..ac72e89 100644
--- a/html/AlleSchichten.php
+++ b/html/AlleSchichten.php
@@ -13,8 +13,7 @@ require '_login.php';
   <link rel="stylesheet" href="css/style_desktop.css" media="screen and (min-width:781px)"/>
   <link rel="stylesheet" href="css/style_mobile.css" media="screen and (max-width:780px)"/>
   <meta name="viewport" content="width=480" />
- 
-  <script src="js/jquery-3.7.1.min.js" type="text/javascript"></script>
+  <script src="<?php echo JQUERY ?>" type="text/javascript"></script> 
   <script src="js/helferdb.js" type="text/javascript"></script>
   <script> collapse_table_rows();
  </script>
diff --git a/html/_login.php b/html/_login.php
index 50e06c2..e166924 100644
--- a/html/_login.php
+++ b/html/_login.php
@@ -49,10 +49,20 @@ if (!isset($_SESSION["HelferID"])) {
   <link rel="stylesheet" href="css/style_desktop.css" media="screen and (min-width:781px)"/>
   <link rel="stylesheet" href="css/style_mobile.css" media="screen and (max-width:780px)"/>
   <script src="js/helferdb.js" type="text/javascript"></script>
+  <script src="<?php echo JQUERY ?>" type="text/javascript"></script>
+  <script>
+  console.log("log","<?php echo JQUERY ?>");
+  window.onload = function() {
+    if (!window.jQuery) {
+       document.getElementById("jquerywarn").innerHTML = "<font size=+2 color=red><b>You have not installed the jquery library!</b></font>";
+    }
+}
+</script>
   <meta name="viewport" content="width=480" />
   <meta charset="utf-8">
 </head>
 <body>
+<div id=jquerywarn></div>
 <form method="post" action="#Info">
 
   <fieldset>
diff --git a/html/index.php b/html/index.php
index 79b9cc7..4fd05d5 100644
--- a/html/index.php
+++ b/html/index.php
@@ -13,11 +13,20 @@ require '_login.php';
   <link rel="stylesheet" href="css/style_desktop.css" media="screen and (min-width:781px)"/>
   <link rel="stylesheet" href="css/style_mobile.css" media="screen and (max-width:780px)"/>
   <script src=js/helferdb.js></script>
+  <script src="<?php echo JQUERY ?>" type="text/javascript"></script>
+  <script>
+  window.onload = function() {
+    if (!window.jQuery) {
+       document.getElementById("jquerywarn").innerHTML = "<font size=+2 color=red><b>You have not installed the jquery library!</b></font>";
+    }
+}
+</script>
 <meta name="viewport" content="width=480" />
 <meta charset="utf-8">
 </head>
 <body>
 <div style="width: 100%;">
+<div id=jquerywarn></div>
 
 <table class="commontable" >
   <tr onclick="window.location.href='Info.php';">