diff --git a/webseite/classes/TopicData.php b/webseite/classes/TopicData.php
index c157c0d..6c315ff 100644
--- a/webseite/classes/TopicData.php
+++ b/webseite/classes/TopicData.php
@@ -127,7 +127,14 @@ class TopicData
     {
         $result = array();
 
+        if(!is_dir(Config::getTopicsDirectory($subjectId))) {
+            return array();
+        }
+
         $topicNames = scandir(Config::getTopicsDirectory($subjectId));
+        if(!$topicNames) {
+            return array();
+        }
 
         usort($topicNames, function ($a, $b) {
             return strcmp($a, $b);
diff --git a/webseite/config/subjects/mathe/properties.json b/webseite/config/subjects/mathe/properties.json
index 5b6cb74..f49e3fe 100644
--- a/webseite/config/subjects/mathe/properties.json
+++ b/webseite/config/subjects/mathe/properties.json
@@ -1,6 +1,6 @@
 {
     "displayName": "Mathe",
-    "description": "Mathe ist blau",
-    "color": "#3b82f6",
+    "description": "Mathe ist rot",
+    "color": "#626cd0",
     "icon": "fa-square-root-alt"
 }
\ No newline at end of file
diff --git a/webseite/config/subjects/physik/properties.json b/webseite/config/subjects/physik/properties.json
new file mode 100644
index 0000000..8f3b5c2
--- /dev/null
+++ b/webseite/config/subjects/physik/properties.json
@@ -0,0 +1,6 @@
+{
+    "displayName": "Physik",
+    "description": "Noch ein Fach",
+    "color": "#363cfc",
+    "icon": "fa-square-root-alt"
+}
\ No newline at end of file
diff --git a/webseite/subjectEditor.php b/webseite/subjectEditor.php
index 45d6296..448da70 100644
--- a/webseite/subjectEditor.php
+++ b/webseite/subjectEditor.php
@@ -6,8 +6,70 @@ require_once("classes/TopicData.php");
 $allSubjects = SubjectData::getAll();
 $editingSubject = null;
 
+$defaultValues = array();
+$defaultValues['displayName'] = "";
+$defaultValues['id'] = "";
+$defaultValues['description'] = "";
+$defaultValues['color'] = "#3b82f6";
+$defaultValues['icon'] = "";
+
+$errors = array();
+
 if (isset($_GET['subjectId'])) {
     $editingSubject = $allSubjects[$_GET['subjectId']];
+
+    $defaultValues['displayName'] = $editingSubject->getDisplayName();
+    $defaultValues['id'] = $editingSubject->getId();
+    $defaultValues['description'] = $editingSubject->getDescription();
+    $defaultValues['color'] = $editingSubject->getColor();
+    $defaultValues['icon'] = $editingSubject->getIcon();
+}
+
+if($_SERVER['REQUEST_METHOD'] == 'POST') {
+    foreach ($defaultValues as $key => $value) {
+        $defaultValues[$key] = $_POST[$key];
+    }
+
+    if(!isset($_POST['displayName']) || trim($_POST['displayName']) == "") {
+        $errors["displayName"] = "Bitte geben Sie einen Namen an.";
+    }
+
+    if(!isset($_POST['id']) || trim($_POST['id']) == "") {
+        $errors["id"] = "Bitte geben Sie eine ID an.";
+    }
+
+    if(!isset($_POST['description']) || trim($_POST['description']) == "") {
+        $errors["description"] = "Bitte geben Sie eine Beschreibung an.";
+    }
+
+    if(!isset($_POST['color']) || trim($_POST['color']) == "") {
+        $errors["color"] = "Bitte geben Sie eine Farbe an.";
+    }
+
+    if(!isset($_POST['icon']) || trim($_POST['icon']) == "") {
+        $errors["icon"] = "Bitte geben Sie ein Icon an.";
+    }
+
+    if(empty($errors)) {
+        $newSubject = false;
+        if(isset($allSubjects[$_POST['id']])) {
+            $newSubject = $allSubjects[$_POST['id']];
+            $newSubject->setDisplayName($_POST['displayName']);
+            $newSubject->setDescription($_POST['description']);
+            $newSubject->setColor($_POST['color']);
+            $newSubject->setIcon($_POST['icon']);
+        } else {
+            $newSubject = SubjectData::createNew($_POST['id'], $_POST['displayName'], $_POST['description'], $_POST['color'], $_POST['icon'], array());
+        }
+
+        if(!$newSubject) {
+            $errors["error"] = "Fehler beim Speichern des Faches.";
+        } else {
+            $newSubject->save();
+            header("Location: " . "subject.php?subject=" . $newSubject->getId());
+        }
+    }
+
 }
 
 ?>
@@ -29,7 +91,7 @@ if (isset($_GET['subjectId'])) {
 
 <body class="min-h-screen bg-gray-50">
 
-<form id="subjectForm" onsubmit="handleSubjectSubmit(event)">
+<form id="subjectForm" method="post" onsubmit="handleSubjectSubmit(event)">
     <div class="space-y-6">
         <div>
             <label class="block text-sm font-medium text-gray-700 mb-2">Name des Fachs</label>
@@ -38,11 +100,17 @@ if (isset($_GET['subjectId'])) {
                    required
                    class="w-full px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-lg enabled:hover:border-gray-400"
                    placeholder="z.B. Mathematik"
-                   value="<?php
-                   if (isset($editingSubject)) {
-                       echo $editingSubject->getDisplayName();
-                   }
-                   ?>">
+                   value="<?php echo $defaultValues['displayName']?>">
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-2">ID des Fachs</label>
+            <input type="text"
+                   name="id"
+                   required
+                   class="w-full px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-lg enabled:hover:border-gray-400"
+                   placeholder="z.B. mathe"
+                   value="<?php echo $defaultValues['id']?>">
         </div>
 
         <div>
@@ -51,26 +119,23 @@ if (isset($_GET['subjectId'])) {
                       required
                       class="w-full px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-lg enabled:hover:border-gray-400"
                       rows="4"
-                      placeholder="Kurze Beschreibung des Fachs"><?php
-                if (isset($editingSubject)) {
-                    echo $editingSubject->getDescription();
-                }
-                ?></textarea>
+                      placeholder="Kurze Beschreibung des Fachs"><?php echo $defaultValues['description']?></textarea>
         </div>
 
         <div>
             <label class="block text-sm font-medium text-gray-700 mb-2">Farbe</label>
             <input type="color" name="color" required
                    class="w-full h-14 px-1 py-1 rounded-lg"
-                   value="<?php
-                   if (isset($editingSubject)) {
-                       echo $editingSubject->getColor();
-                   } else {
-                       echo "#3b82f6";
-                   }
-                   ?>">
+                   value="<?php echo $defaultValues['color']?>">
         </div>
 
+        <div>
+            <label for="iconSelect" class="block text-sm font-medium text-gray-700">Icon</label>
+            <input class="mt-1 block w-full rounded-lg border-gray-300 shadow-sm" type="text" name="icon"
+                   id="iconSelect" value="<?php echo $defaultValues['icon']?>">
+        </div>
+
+        <!--
         <div>
             <label class="block text-sm font-medium text-gray-700 mb-2">Icon auswählen</label>
             <div class="grid grid-cols-6 gap-4 p-4 border rounded-lg bg-gray-50">
@@ -95,6 +160,10 @@ if (isset($_GET['subjectId'])) {
                     'fa-tablets',
                 ];
 
+                if(isset($editingSubject)) {
+                    $icons[] = $editingSubject->getIcon();
+                }
+
                 foreach ($icons as $icon) {
                     echo "<div class='icon-option cursor-pointer p-4 rounded-lg hover:bg-white hover:shadow transition-all text-center' 
                                       onclick='selectIcon(this, \"$icon\")' data-icon='$icon'>
@@ -105,8 +174,17 @@ if (isset($_GET['subjectId'])) {
             </div>
             <input type="hidden" name="icon" id="selectedIcon">
         </div>
+        -->
+
+        <?php
+        foreach ($errors as $error) {
+            echo "<p class='text-red-800'>$error</p>";
+        }
+        ?>
+
     </div>
 
+
     <div class="mt-8 flex justify-end gap-3">
         <button type="button" onclick="closeModal()"
                 class="px-6 py-3 text-gray-600 hover:text-gray-800 text-lg">
@@ -114,7 +192,7 @@ if (isset($_GET['subjectId'])) {
         </button>
         <button type="submit"
                 class="px-6 py-3 bg-blue-600 text-white rounded-lg hover:bg-blue-700 text-lg">
-            Fach erstellen
+            Speichern
         </button>
     </div>
 </form>