--- step-3/index.html	2016-09-17 21:44:04.000000000 +0200
+++ step-4/index.html	2016-09-17 21:44:04.000000000 +0200
@@ -1,6 +1,6 @@
 <html>
   <head>
-    <title>Step 3: adding map controls</title>
+    <title>Step 4: unfolding the overview map by default</title>
     <script src="../OpenLayers.js"></script>
     <script src="../OpenStreetMap.js"></script>
     <script>
@@ -12,17 +12,20 @@
         projLonLat   = new OpenLayers.Projection("EPSG:4326");   // WGS 1984
         projMercator = new OpenLayers.Projection("EPSG:900913"); // Spherical Mercator
 
+        overviewMap = new OpenLayers.Control.OverviewMap();
+
         map = new OpenLayers.Map("demoMap", 
                                  { controls: [ new OpenLayers.Control.Navigation(),    // direct panning via mouse drag
                                                new OpenLayers.Control.Attribution(),   // attribution text
+                                               new OpenLayers.Control.MousePosition(),    // where am i?
                                                new OpenLayers.Control.PanZoomBar(),    // larger navigation control
-                                               new OpenLayers.Control.MousePosition({'displayProjection': projMercator})    // mouse position
-                                               new OpenLayers.Control.OverviewMap()    // overview map
+                                               overviewMap                             // overview map
                                              ]
                                  } 
                                 );
         map.addLayer(new OpenLayers.Layer.OSM.Mapnik());
         map.setCenter(new OpenLayers.LonLat(lon, lat).transform(projLonLat,projMercator), zoom);
+        overviewMap.maximizeControl();
       }
     </script>
   </head>