diff --git a/addKatalog.htm b/addKatalog.htm
index 4fa4284..7827279 100644
--- a/addKatalog.htm
+++ b/addKatalog.htm
@@ -8,7 +8,7 @@
 </head>
 <body>
     <div class="Titel">
-        <a href="index.html"><button id= zurueck">zurück</button></a>
+        <a href="index.html"><button id= "zurueck">zurück</button></a>
         <h1>Katalog</h1>
     </div>
 
diff --git a/changeKatalog.htm b/changeKatalog.htm
index 4fa4284..7827279 100644
--- a/changeKatalog.htm
+++ b/changeKatalog.htm
@@ -8,7 +8,7 @@
 </head>
 <body>
     <div class="Titel">
-        <a href="index.html"><button id= zurueck">zurück</button></a>
+        <a href="index.html"><button id= "zurueck">zurück</button></a>
         <h1>Katalog</h1>
     </div>
 
diff --git a/deleteKatalog.htm b/deleteKatalog.htm
index 66ddfe6..df551bc 100644
--- a/deleteKatalog.htm
+++ b/deleteKatalog.htm
@@ -8,7 +8,7 @@
 </head>
 <body>
     <div class="Titel">
-        <a href="index.html"><button id= zurueck">zurück</button></a>
+        <a href="index.html"><button id= "zurueck">zurück</button></a>
         <h1>Katalog</h1>
     </div>
 
diff --git a/findKatalog.htm b/findKatalog.htm
index aa715de..96438bf 100644
--- a/findKatalog.htm
+++ b/findKatalog.htm
@@ -8,7 +8,7 @@
 </head>
 <body>
     <div class="Titel">
-        <a href="index.html"><button id= zurueck">zurück</button></a>
+        <a href="index.html"><button id= "zurueck">zurück</button></a>
         <h1>Katalog</h1>
     </div>
 
diff --git a/index.html b/index.html
index 1159a44..da1894d 100644
--- a/index.html
+++ b/index.html
@@ -34,10 +34,10 @@
                         Buch im Inventar
                         <select name="selection" id="selection" onchange="location.assign(this.value);">
                             <option></option>
-                            <option value=find.html>Finden</option>
-                            <Option value="add.html">Hinzufügen</Option>
-                            <option value="change.html">Bearbeiten</option>
-                            <option value="delete.html">Löschen</option>
+                            <option value=findInventar.htm>Finden</option>
+                            <Option value="addInventar.htm">Hinzufügen</Option>
+                            <option value="changeInventar.htm">Bearbeiten</option>
+                            <option value="deleteInventar.htm">Löschen</option>
                         </select>
                     </dd>
                     <dt>
