diff --git a/assetclass.php b/assetclass.php
index ababa8e..b7e8ff0 100644
--- a/assetclass.php
+++ b/assetclass.php
@@ -60,6 +60,13 @@ switch ($submit = form_get_action()) {
         break;
 
     case 'delete':
+        $sth = $dbh->prepare("SELECT COUNT(*) FROM asset WHERE assetclass_id=?");
+        $sth->execute([$id]);
+        if ($sth->fetchColumn() > 0) {
+            $g_warning->Add("Objektklasse kann nicht gelöscht werden, da noch zugeordnete Objekte vorhanden sind.");
+            $action = ACT_VIEW;
+            break;
+        }
         $sth = $dbh->prepare("DELETE FROM assetclass WHERE assetclass_id=?");
         try {
             $sth->execute([$id]);
diff --git a/assetclassgroup.php b/assetclassgroup.php
index cd2602b..87e8c49 100644
--- a/assetclassgroup.php
+++ b/assetclassgroup.php
@@ -59,6 +59,13 @@ switch ($submit = form_get_action()) {
         break;
 
     case 'delete':
+        $sth = $dbh->prepare("SELECT COUNT(*) FROM assetclass WHERE assetclassgroup_id=?");
+        $sth->execute([$id]);
+        if ($sth->fetchColumn() > 0) {
+            $g_warning->Add("Objektklassengruppe kann nicht gelöscht werden, da noch zugeordnete Objektklassen vorhanden sind.");
+            $action = ACT_VIEW;
+            break;
+        }
         $sth = $dbh->prepare("DELETE FROM assetclassgroup WHERE assetclassgroup_id=?");
         try {
             $sth->execute([$id]);
diff --git a/location.php b/location.php
index 6ab2f83..87008a7 100644
--- a/location.php
+++ b/location.php
@@ -118,7 +118,14 @@ switch ($submit = form_get_action()) {
         break;
 
     case 'delete':
+        $sth = $dbh->prepare("DELETE FROM subnetlocation WHERE location_id=?");
+        $sth->execute([$id]);
+        $n = $sth->rowCount();
+        if ($n > 0) {
+            $g_message->Add("$n Subnetzzuordnungen wurden entfernt.");
+        }
         $sth = $dbh->prepare("DELETE FROM location WHERE location_id=?");
+        $g_message->Add("Standort wurde gelöscht.");
         $sth->execute([$id]);
         $action = ACT_DEFAULT;
         break;
diff --git a/tpl/style.css b/tpl/style.css
index 7169cdc..1b821f7 100644
--- a/tpl/style.css
+++ b/tpl/style.css
@@ -210,7 +210,7 @@ div.error, div.warning, div.info, div.note {
     margin: 1em 0 0 0;
     border-radius: 12px;
     width: 750px;
-    animation: fadeout 10s 2s forwards;
+    animation: fadeout 2s 10s forwards;
 }
 div.error {
     border: 1px solid #8b0000;
diff --git a/tpl/vlanview.tpl b/tpl/vlanview.tpl
index cd1faf3..1f14c7f 100644
--- a/tpl/vlanview.tpl
+++ b/tpl/vlanview.tpl
@@ -79,7 +79,7 @@
     </td>
     <td class="value">
         {foreach item=subnet from=$subnets}
-        <a href="subnet.php?f=wiew&id={$subnet.subnet_id}">{$subnet.subnet_address}/{$subnet.subnet_mask}</a>
+        <a href="subnet.php?f=view&id={$subnet.subnet_id}">{$subnet.subnet_address}/{$subnet.subnet_mask}</a>
 	{$subnet.subnet_info}
 	<br>
         {/foreach}
diff --git a/vlan.php b/vlan.php
index daa5c88..4c20596 100644
--- a/vlan.php
+++ b/vlan.php
@@ -88,6 +88,12 @@ switch ($submit = form_get_action()) {
         break;
 
     case 'delete':
+        $sth = $dbh->prepare("DELETE FROM subnetvlan WHERE vlan_id=?");
+        $sth->execute([$id]);
+        $n = $sth->rowCount();
+        if ($n > 0) {
+            $g_message->Add("$n vlan to subnet references were removed.");
+        }
         $sth = $dbh->prepare("DELETE FROM vlan WHERE vlan_id=?");
         $sth->execute([$id]);
         $g_message->Add(_("VLAN deleted."));
diff --git a/zone.php b/zone.php
index 01e4503..1a597b8 100644
--- a/zone.php
+++ b/zone.php
@@ -83,6 +83,13 @@ switch ($submit = form_get_action()) {
         break;
 
     case 'delete':
+        $sth = $dbh->prepare("SELECT COUNT(*) FROM node WHERE zone_id=?");
+        $sth->execute([$id]);
+        if ($sth->fetchColumn() > 0) {
+            $g_warning->Add("Zone can not be removed. There are node-references.");
+            $action = ACT_VIEW;
+            break;
+        }
         $sth = $dbh->prepare("DELETE FROM zone WHERE zone_id=?");
         $sth->execute([$id]);
         $g_message->Add(_("Deleted zone"));