diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java
index 4fc35ac91..65b33f6a8 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java
@@ -50,11 +50,12 @@ public class AdvancedAllocationController extends GenericForwardComposer
     private Div insertionPointRightPanel;
     private Div insertionPointTimetracker;
     private TimeTrackedTableWithLeftPane<FakeDataLeft, FakeData> timeTrackedTableWithLeftPane;
+    private TimeTracker timeTracker;
 
     @Override
     public void doAfterCompose(Component comp) throws Exception {
         super.doAfterCompose(comp);
-        TimeTracker timeTracker = new TimeTracker(createExampleInterval());
+        timeTracker = new TimeTracker(createExampleInterval());
         this.timeTrackedTableWithLeftPane = new TimeTrackedTableWithLeftPane<FakeDataLeft, FakeData>(
                 getDataSource(), getColumnsForLeft(), getLeftRenderer(),
                 getRightRenderer(), timeTracker);
@@ -71,6 +72,14 @@ public class AdvancedAllocationController extends GenericForwardComposer
         timetracker.afterCompose();
     }
 
+    public void onClick$zoomIncrease() {
+        timeTracker.goToNextDetailLevel();
+    }
+
+    public void onClick$zoomDecrease() {
+        timeTracker.goToPreviousDetailLvel();
+    }
+
     private ICellForDetailItemRenderer<FakeColumn, FakeDataLeft> getLeftRenderer() {
         return new ICellForDetailItemRenderer<FakeColumn, FakeDataLeft>() {
 
diff --git a/navalplanner-webapp/src/main/webapp/planner/advance_allocation.zul b/navalplanner-webapp/src/main/webapp/planner/advance_allocation.zul
index a99a38cbf..afc6a1e95 100644
--- a/navalplanner-webapp/src/main/webapp/planner/advance_allocation.zul
+++ b/navalplanner-webapp/src/main/webapp/planner/advance_allocation.zul
@@ -34,8 +34,8 @@
         <button label="Back" />
         <button label="Company view" />
         <separator/>
-        <button label="+" />
-        <button label="-" />
+        <button label="+" id="zoomIncrease"/>
+        <button label="-" id="zoomDecrease"/>
         From: <datebox /> to: <datebox />
         <separator/>
         Filter: