diff --git a/src/main/java/org/gcube/portlets/user/workspace/client/view/tree/AsyncTreePanel.java b/src/main/java/org/gcube/portlets/user/workspace/client/view/tree/AsyncTreePanel.java
index c41110c..6395fe8 100644
--- a/src/main/java/org/gcube/portlets/user/workspace/client/view/tree/AsyncTreePanel.java
+++ b/src/main/java/org/gcube/portlets/user/workspace/client/view/tree/AsyncTreePanel.java
@@ -55,7 +55,8 @@ import com.google.gwt.user.client.ui.AbstractImagePrototype;
  */
 public class AsyncTreePanel extends LayoutContainer {
 
-//	private TreeLoader<FileModel> loader;
+private static final String TREE_MESSAGE_PANEL_ASYNC = "treeMessagePanelAsync";
+	//	private TreeLoader<FileModel> loader;
 	private TreePanel<FileModel> treePanel;
 	private TreeStore<FileModel> store;
 	private ContextMenuTree contextMenuTree;
@@ -128,7 +129,7 @@ public class AsyncTreePanel extends LayoutContainer {
 		treePanel.setDisplayProperty(ConstantsExplorer.NAME);
 		
 		// statefull components need a defined id
-		treePanel.setId("treeMessagePanelAsync");
+		treePanel.setId(TREE_MESSAGE_PANEL_ASYNC);
 
 		// SET icons in tree panel
 		treePanel.setIconProvider(new ModelIconProvider<FileModel>() {