diff --git a/ConfigParameters.md b/ConfigParameters.md
index 612eb6b8..78964e8e 100644
--- a/ConfigParameters.md
+++ b/ConfigParameters.md
@@ -27,8 +27,20 @@ The options are:
 * readOnly: Set to true if the viewer should not be able to edit the map.
 * zoom: how much the map should be zoomed.
 * size: size of the map area.
-* viewport
+* viewPort: set this to the same as the size
 * persistenceManager: Classname of a class that extends mindplot.PersistenceManager (see ImplementingPersistence for more info.)
 * mapId: The id of the map
 * container: The id of the containing div.
 
+Viewport and size should be set like this::
+
+        var containerSize = {
+            height: parseInt(screen.height),
+            width:  parseInt(screen.width)
+        };
+
+        var viewPort = {
+            height: parseInt(window.innerHeight - 70), // Footer and Header
+            width:  parseInt(window.innerWidth)
+        };
+
diff --git a/ImplementingPersistence.md b/ImplementingPersistence.md
new file mode 100644
index 00000000..0a0e45dc
--- /dev/null
+++ b/ImplementingPersistence.md
@@ -0,0 +1,86 @@
+# Implementing custom storage
+
+To implement a custom backend, you need to create your own implementation of the mindplot.PersistenceManager class. 
+
+Here is an example skeleton::
+
+function createStorageManager(mindplot) {
+    mindplot.RestStorageManager = new Class({
+        Extends:mindplot.PersistenceManager,
+        initialize: function(url) {
+            this.parent();
+            this.backendUrl = url;
+        },
+
+        saveMapXml : function(mapId, mapXml, pref, saveHistory, events) {
+            var url = this.backendUrl  + mapId;
+            var xmlRequest = new Request({
+                url: url,
+                method: 'post',
+                async: false,
+                onSuccess: function(responseText) {
+                    events.onSuccess();        
+                }, 
+                onError: function (text, error) {
+                    console.log("Error saving mindmap to: " + url, text, error);
+                    events.onError();
+                }
+            });
+            xmlRequest.send();
+        },
+
+        loadMapDom : function(mapId) {
+                var xmlRequest = new Request({
+                    url: this.backendUrl  + mapId,
+                    method: 'get',
+                    async: false,
+                    onSuccess: function(responseText) {
+                        xml = responseText;
+                    }
+                });
+                xmlRequest.send();
+
+                // If I could not load it from a file, hard code one.
+                if (xml == null) {
+                    throw "Map could not be loaded";
+                }
+            return core.Utils.createDocumentFromText(xml);
+        }
+
+    }
+    );
+    return new mindplot.RestStorageManager(url);
+}
+
+
+In your script for loading the mindmap you add a call to the callback into the loadcomplete method::
+
+     $(document).addEvent('loadcomplete', function(resource) {
+               //Asset.javascript("{{ asset('bundles/fpgadmin/js/FpgMindmapPersistence.js')}}");
+               // Options has been defined in by a external ile ?
+               var options = {
+                    'persistenceManager' : createStorageManager(mindplot, "http://localhost/my/rest/interface");    
+                    viewPort: {
+                        height: parseInt(window.innerHeight - 70), // Footer and Header
+                        width:  parseInt(window.innerWidth)
+                    },
+                    size : {
+                    height: parseInt(screen.height),
+                    width:  parseInt(screen.width)
+                },
+                "readOnly":false,
+                "zoom":1.3,
+                "container":"mindplot"
+                "mapId" : "myMapId"
+               };
+               var designer = buildDesigner(options);
+               var persistence = mindplot.PersistenceManager.getInstance();
+               var mindmap;
+               try {
+                   mindmap = persistence.load(mapId);
+               } catch(e) {
+                   // If the map could not be loaded, create a new empty map...
+                   mindmap = mindplot.model.Mindmap.buildEmpty(mapId);
+               }
+               designer.loadMap(mindmap);
+           });
diff --git a/README.md b/README.md
index 6cb2d621..1b9d08a2 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,13 @@ This will start the application on the URL: http://localhost:8080/wise-webapp/.
 
 User: test@wisemapping.org
 
+
+## Running the JS only version
+
+Start by creating the .zip file: 
+
+`mvn assembly:assembly -Dmaven.test.skip=true`
+
 ## Author
 
    * Pablo Luna