diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java
index cbf0a051a..42ea2c740 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java
@@ -31,7 +31,6 @@ import java.util.List;
 import java.util.Set;
 
 import org.apache.commons.logging.LogFactory;
-import org.hibernate.validator.InvalidValue;
 import org.joda.time.LocalDate;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.common.exceptions.ValidationException;
@@ -45,10 +44,9 @@ import org.navalplanner.web.common.MessagesForUser;
 import org.navalplanner.web.common.OnlyOneVisible;
 import org.navalplanner.web.common.Util;
 import org.navalplanner.web.common.components.Autocomplete;
+import org.navalplanner.web.util.ValidationExceptionPrinter;
 import org.navalplanner.web.workreports.WorkReportCRUDController;
-import org.zkoss.ganttz.util.ComponentsFinder;
 import org.zkoss.zk.ui.Component;
-import org.zkoss.zk.ui.WrongValueException;
 import org.zkoss.zk.ui.event.CheckEvent;
 import org.zkoss.zk.ui.event.Event;
 import org.zkoss.zk.ui.event.EventListener;
@@ -175,7 +173,7 @@ public class CostCategoryCRUDController extends GenericForwardComposer
         try {
             costCategoryModel.validateHourCostsOverlap();
         } catch (ValidationException e) {
-            showHoursCostsOverlapValidationException(e);
+            ValidationExceptionPrinter.showAt(listHourCosts, e);
         }
 
         try {
@@ -189,15 +187,6 @@ public class CostCategoryCRUDController extends GenericForwardComposer
         return false;
     }
 
-    private void showHoursCostsOverlapValidationException(ValidationException e) {
-        InvalidValue invalid = e.getInvalidValue();
-        Row comp = ComponentsFinder.findRowByValue(listHourCosts,
-                invalid.getValue());
-        if (comp != null) {
-            throw new WrongValueException(comp, invalid.getMessage());
-        }
-    }
-
     public CostCategory getCostCategory() {
         return costCategoryModel.getCostCategory();
     }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/ResourcesCostCategoryAssignmentController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/ResourcesCostCategoryAssignmentController.java
index 3609788bf..105cc533d 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/ResourcesCostCategoryAssignmentController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/ResourcesCostCategoryAssignmentController.java
@@ -27,7 +27,6 @@ import java.util.Date;
 import java.util.List;
 
 import org.apache.commons.logging.LogFactory;
-import org.hibernate.validator.InvalidValue;
 import org.joda.time.LocalDate;
 import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.costcategories.entities.CostCategory;
@@ -39,10 +38,9 @@ import org.navalplanner.web.common.Level;
 import org.navalplanner.web.common.MessagesForUser;
 import org.navalplanner.web.common.Util;
 import org.navalplanner.web.common.components.Autocomplete;
+import org.navalplanner.web.util.ValidationExceptionPrinter;
 import org.navalplanner.web.workreports.WorkReportCRUDController;
-import org.zkoss.ganttz.util.ComponentsFinder;
 import org.zkoss.zk.ui.Component;
-import org.zkoss.zk.ui.WrongValueException;
 import org.zkoss.zk.ui.event.Event;
 import org.zkoss.zk.ui.event.EventListener;
 import org.zkoss.zk.ui.event.Events;
@@ -334,13 +332,9 @@ public class ResourcesCostCategoryAssignmentController extends GenericForwardCom
         try {
             CostCategory.validateCostCategoryOverlapping(costCategoryAssignments);
         } catch (ValidationException e) {
-            InvalidValue invalidValue = e.getInvalidValue();
-            Component comp = ComponentsFinder.findRowByValue(
-                    listResourcesCostCategoryAssignments,
-                    invalidValue.getValue());
-            throw new WrongValueException(comp, invalidValue.getMessage());
+            ValidationExceptionPrinter.showAt(listResourcesCostCategoryAssignments, e);
         }
         return true;
     }
 
-}
+}
\ No newline at end of file
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/util/ValidationExceptionPrinter.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/util/ValidationExceptionPrinter.java
new file mode 100644
index 000000000..f2834a15a
--- /dev/null
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/util/ValidationExceptionPrinter.java
@@ -0,0 +1,60 @@
+/*
+ * This file is part of NavalPlan
+ *
+ * Copyright (C) 2011 Igalia S.L
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.navalplanner.web.util;
+
+import org.hibernate.validator.InvalidValue;
+import org.navalplanner.business.common.exceptions.ValidationException;
+import org.zkoss.ganttz.util.ComponentsFinder;
+import org.zkoss.zk.ui.Component;
+import org.zkoss.zk.ui.WrongValueException;
+import org.zkoss.zul.Grid;
+import org.zkoss.zul.Row;
+
+/**
+ *
+ * @author Diego Pino García <dpino@igalia.com>
+ *
+ *         Helper class for printing a {@link ValidationException} at a
+ *         component.
+ *
+ */
+public class ValidationExceptionPrinter {
+
+    public static void showAt(Component comp, ValidationException e) {
+        InvalidValue invalidValue = e.getInvalidValue();
+        if (comp instanceof Grid) {
+            showAt((Grid) comp, invalidValue);
+        } else {
+            showAt(comp, invalidValue);
+        }
+    }
+
+    private static void showAt(Component comp, InvalidValue invalidValue) {
+        throw new WrongValueException(comp, invalidValue.getMessage());
+    }
+
+    private static void showAt(Grid comp, InvalidValue invalidValue) {
+        Row row = ComponentsFinder.findRowByValue(comp, invalidValue.getValue());
+        if (row != null) {
+            throw new WrongValueException(row, invalidValue.getMessage());
+        }
+    }
+
+}
\ No newline at end of file