diff --git a/routeSQL.php b/routeSQL.php
index ad6083d..9cefb74 100644
--- a/routeSQL.php
+++ b/routeSQL.php
@@ -276,9 +276,10 @@ class routeSQL
 	  /** Add HTML routes */
 	  $route = new route ();
     $route->allowSlashes=false;
-	  $route->get ($this->url_prefix."/", function () use ($route)
+	  $route->get ($this->url_prefix."/", function ($chain) use ($route)
     {
-      $route->redirect ("/".$this->url_prefix, "");
+      $route->redirect ("/".str_replace ("{chain}", $chain, $this->url_prefix),
+                        "");
     });
 
 	  $route->get ($this->url_prefix.
@@ -365,16 +366,16 @@ class routeSQL
       }
       $nbentries = count ($datas);
       if ($num > 1000)
-        $route->redirect ("/".$this->url_prefix.
-                          "?page=$page&num=1000&search=$search", "");
+        $route->redirect ("/".str_replace ("{chain}", $chain, $this->url_prefix)
+                          ."?page=$page&num=1000&search=$search", "");
       if ($page < 1)
-        $route->redirect ("/".$this->url_prefix.
-                          "?page=1&num=$num&search=$search", "");
+        $route->redirect ("/".str_replace ("{chain}", $chain, $this->url_prefix)
+                          . "?page=1&num=$num&search=$search", "");
       // Push on the last page if the values are too high
       if ($nbentries > 0 && ($page-1)*$num > $nbentries)
       {
         $maxPage = intval ($nbentries/$num)+1;
-        $route->redirect ("/".$this->url_prefix.
+        $route->redirect ("/".str_replace("{chain}", $chain, $this->url_prefix).
                           "?page=$maxPage&num=$num&search=$search", "");
       }
 
@@ -553,12 +554,16 @@ echo $content;
       {
         $csrf->checkToken ($token);
         $this->objectDB->delete ($id);
-        $route->redirect ("/".$this->url_prefix, "");
+        $route->redirect ("/".
+                          str_replace ("{chain}", $chain, $this->url_prefix),
+                          "");
       }
       catch (Exception $e)
       {
         $renderer->flash ("ERROR", $e->getMessage());
-        $route->redirect ("/".$this->url_prefix, "");
+        $route->redirect ("/".
+                          str_replace ("{chain}", $chain, $this->url_prefix),
+                          "");
       }
 
 
@@ -644,6 +649,11 @@ echo $content;
           $field->mandatory = true;
         if (in_array ("autoincrement", $this->objectDB->fields[$key]))
           $field->type = "hidden";
+        if ($key === $this->chainedForeign)
+        {
+          $field->defaults = $chain;
+          $field->readonly = true;
+        }
         $fields[] = $field;
         unset ($field);
       }
@@ -694,7 +704,9 @@ echo $content;
           $this->objectDB->insert ($values);
           $renderer = new renderer (); 
           $renderer->flash ("SUCCESS", _("Creation done"));
-          $route->redirect ("/".$this->url_prefix, "");
+          $route->redirect ("/".
+                            str_replace ("{chain}", $chain, $this->url_prefix),
+                            "");
         }
         catch (Exception $e)
         {
@@ -712,7 +724,8 @@ echo $content;
       // corrected
       $_SESSION["domframework"]["routeSQL"]["errors"] = $errors;
       $_SESSION["domframework"]["routeSQL"]["values"] = $values;
-      $route->redirect ("/".$this->url_prefix."/add", "");
+      $route->redirect ("/".str_replace("{chain}", $chain, $this->url_prefix).
+                        "/add", "");
 
 	  });
 
@@ -801,6 +814,11 @@ echo $content;
           $field->type = "hidden";
         if ($readonly === true || $this->readwriteAllowed === false)
           $field->readonly = true;
+        if ($key === $this->chainedForeign)
+        {
+          $field->defaults = $chain;
+          $field->readonly = true;
+        }
         $fields[] = $field;
         unset ($field);
       }
@@ -854,15 +872,24 @@ echo $content;
       if ($values[$this->objectDB->primary] !== $id)
         throw new Exception (dgettext("domframework",
                                       "Can not change the primary key"), 403);
+      $errorsChain = array ();
+      if ($this->chainedForeign !== null &&
+          $values[$this->chainedForeign] !== $chain)
+        $errorsChain[$this->chainedForeign] = 
+          array ("error", dgettext("domframework",
+                                   "Can not change the external key"));
+
       $errors = $this->objectDB->verify ($values, $id);
-      if (count ($errors) == 0)
+      if (count ($errors) == 0 && count ($errorsChain) == 0)
       {
         try
         {
           $this->objectDB->update ($id, $values);
           $renderer = new renderer (); 
           $renderer->flash ("SUCCESS", _("Update done"));
-          $route->redirect ("/".$this->url_prefix, "");
+          $route->redirect ("/".
+                            str_replace ("{chain}", $chain, $this->url_prefix),
+                            "");
         }
         catch (Exception $e)
         {
@@ -875,12 +902,15 @@ echo $content;
         $renderer = new renderer ();
         foreach ($errors as $error)
           $renderer->flash (strtoupper ($error[0]), $error[1]);
+        foreach ($errorsChain as $error)
+          $renderer->flash (strtoupper ($error[0]), $error[1]);
       }
       // If errors : save them and redirect to the page of editing to be
       // corrected
       $_SESSION["domframework"]["routeSQL"]["errors"] = $errors;
       $_SESSION["domframework"]["routeSQL"]["values"] = $values;
-      $route->redirect ("/".$this->url_prefix."/$id", "");
+      $route->redirect ("/".str_replace ("{chain}", $chain, $this->url_prefix).
+                        "/$id", "");
 	  });
   }