--- a/samples/main-grid-topology.cc	Wed Jan 02 09:09:24 2008 +0100
+++ b/samples/main-grid-topology.cc	Wed Jan 02 09:25:31 2008 +0100
@@ -39,7 +39,7 @@
        j != nodes.end (); j++)
     {
       Ptr<Object> object = *j;
-      Ptr<MobilityModel> position = object->QueryInterface<MobilityModel> (MobilityModel::iid);
+      Ptr<MobilityModel> position = object->QueryInterface<MobilityModel> ();
       NS_ASSERT (position != 0);
       Vector pos = position->GetPosition ();
       std::cout << "x=" << pos.x << ", y=" << pos.y << ", z=" << pos.z << std::endl;