diff --git a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/GeoportalDataViewer.java b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/GeoportalDataViewer.java
index 7faf54f..523cd43 100644
--- a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/GeoportalDataViewer.java
+++ b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/GeoportalDataViewer.java
@@ -1,5 +1,7 @@
 package org.gcube.portlets.user.geoportaldataviewer.client;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Set;
@@ -231,10 +233,20 @@ public class GeoportalDataViewer implements EntryPoint {
 										"//cdnjs.cloudflare.com/ajax/libs/nanogallery2/3.0.5/jquery.nanogallery2.min.js")
 										.setWindow(ScriptInjector.TOP_WINDOW).inject();
 
+								if (result.getAvailableCollections() == null
+										|| result.getAvailableCollections().size() == 0) {
+									RootPanel.get(APP_DIV).remove(loaderApp);
+									Window.alert("No available collection in this context");
+									RootPanel.get(APP_DIV).add(getGeneralErrorPanel());
+									return;
+								}
+
 								GWT.log("Loading collections, count " + result.getAvailableCollections().size());
 
-								mainPanel.setAvailableCollections(result.getAvailableCollections().values(),
-										paramGeonaItemType);
+								ArrayList<GCubeCollection> listColl = new ArrayList<GCubeCollection>();
+								listColl.addAll(result.getAvailableCollections().values());
+								Collections.sort(listColl);
+								mainPanel.setAvailableCollections(listColl, paramGeonaItemType);
 
 								if (paramGeonaItemID != null) {
 									if (paramGeonaItemType == null) {
@@ -592,17 +604,17 @@ public class GeoportalDataViewer implements EntryPoint {
 			@Override
 			public void onShowPopup(ShowPopupOnCentroidEvent showPopupOnCentroiEvent) {
 				GWT.log("ShowPopupOnCentroidEvent: " + showPopupOnCentroiEvent);
-				
-				//Showing popup after clicking on map
+
+				// Showing popup after clicking on map
 				if (showPopupOnCentroiEvent.getProfileID() != null && showPopupOnCentroiEvent.getProjectID() != null) {
 					Coordinate transfCoord = MapUtils
 							.geoJSONTToBBoxCenter(showPopupOnCentroiEvent.getSpatialReference(), null, null);
 
 					performWFSQueryOnCentroid(showPopupOnCentroiEvent.getProjectID(), transfCoord.getX(),
 							transfCoord.getY());
-					
-				//Showing popup after locate on Map
-				}else if(showPopupOnCentroiEvent.getProjectView()!=null) {
+
+					// Showing popup after locate on Map
+				} else if (showPopupOnCentroiEvent.getProjectView() != null) {
 					layerManager.showPopupInfoForCentroidLayer(showPopupOnCentroiEvent.getProjectView());
 				}
 
diff --git a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.java b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.java
index 9ada671..ed89854 100644
--- a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.java
+++ b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.java
@@ -187,6 +187,14 @@ public class GeonaDataViewMainPanel extends Composite {
 		navListSearch.addItem(PLACEHOLDER_SELECT_SEARCH_IN, PLACEHOLDER_SELECT_SEARCH_IN);
 		
 		navListSearch.getElement().getFirstChildElement().setAttribute("disabled", "disabled");
+		
+//		List<UseCaseDescriptorDV> listUCDs = new ArrayList<UseCaseDescriptorDV>();
+//		
+//		for (ItemFieldsResponse itemFieldsResponse : itemFieldsReponse) {
+//			listUCDs.add(itemFieldsResponse.getUseCaseDescriptorDV());
+//		}
+//		
+//		Collections.sort(listUCDs);
 
 		for (final ItemFieldsResponse itemFieldResp : itemFieldsReponse) {
 
diff --git a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.ui.xml b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.ui.xml
index 9208321..24aa44d 100644
--- a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.ui.xml
+++ b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/ui/GeonaDataViewMainPanel.ui.xml
@@ -52,7 +52,7 @@
 				<b:DropdownButton type="LINK"
 					text="Open Collection" ui:field="openCollectionDropDown">
 					<g:HTMLPanel ui:field="openCollectionPanel"
-						addStyleNames="{style.open-collection-style}">
+						addStyleNames="open-collection-style">
 					</g:HTMLPanel>
 				</b:DropdownButton>
 				<b:DropdownButton type="LINK"
diff --git a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/shared/GCubeCollection.java b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/shared/GCubeCollection.java
index cb8014f..7e51c3f 100644
--- a/src/main/java/org/gcube/portlets/user/geoportaldataviewer/shared/GCubeCollection.java
+++ b/src/main/java/org/gcube/portlets/user/geoportaldataviewer/shared/GCubeCollection.java
@@ -1,40 +1,37 @@
 package org.gcube.portlets.user.geoportaldataviewer.shared;
 
-
 import java.io.Serializable;
 import java.util.List;
 
 import org.gcube.application.geoportalcommon.shared.geoportal.materialization.IndexLayerDV;
 import org.gcube.application.geoportalcommon.shared.geoportal.ucd.UseCaseDescriptorDV;
 
+public class GCubeCollection implements Serializable, Comparable<GCubeCollection> {
 
-public class GCubeCollection implements Serializable {
-
-    /**
+	/**
 	 * 
 	 */
 	private static final long serialVersionUID = -3915546050671671465L;
-	
+
 	private UseCaseDescriptorDV ucd;
-    private List<IndexLayerDV> indexes;
-	
-    public GCubeCollection() {
+	private List<IndexLayerDV> indexes;
+
+	public GCubeCollection() {
 	}
-	
+
 	public UseCaseDescriptorDV getUcd() {
 		return ucd;
 	}
-    
-    public List<IndexLayerDV> getIndexes() {
+
+	public List<IndexLayerDV> getIndexes() {
 		return indexes;
 	}
-	
-    
-    public void setUcd(UseCaseDescriptorDV ucd) {
+
+	public void setUcd(UseCaseDescriptorDV ucd) {
 		this.ucd = ucd;
 	}
-    
-    public void setIndexes(List<IndexLayerDV> indexes) {
+
+	public void setIndexes(List<IndexLayerDV> indexes) {
 		this.indexes = indexes;
 	}
 
@@ -42,6 +39,24 @@ public class GCubeCollection implements Serializable {
 	public String toString() {
 		return "GCubeCollection [ucd=" + ucd + ", indexes=" + indexes + "]";
 	}
-    
-    
+
+	@Override
+	public int compareTo(GCubeCollection o) {
+
+		if (this == null || this.ucd == null)
+			return 1;
+
+		if (o == null || o.getUcd() == null)
+			return -1;
+
+		if (this.ucd.getName() == null)
+			return 1;
+
+		if (o.getUcd().getName() == null)
+			return -1;
+
+		return this.getUcd().getName().compareTo(o.getUcd().getName());
+
+	}
+
 }
diff --git a/src/main/webapp/GeoportalDataViewer.css b/src/main/webapp/GeoportalDataViewer.css
index 78893b9..07aff81 100644
--- a/src/main/webapp/GeoportalDataViewer.css
+++ b/src/main/webapp/GeoportalDataViewer.css
@@ -771,6 +771,19 @@ RESPONSIVE
 }
 
 /* OPEN COLLECTION UI */
+.open-collection-style {
+	padding-left: 10px;
+	padding-right: 10px;
+}
+
+.open-collection-style > div {
+	border: 1px solid #ccc !important;
+	border-radius: 5px;
+	padding: 10px;
+	margin-bottom: 10px;
+	margin-top: 5px;
+}
+
 .layer-style-panel {
 	margin-left: 25px;
 	font-size: 13px;