diff --git a/Modules/IGTUI/Qmitk/QmitkNavigationToolManagementWidget.cpp b/Modules/IGTUI/Qmitk/QmitkNavigationToolManagementWidget.cpp
index f6f9a54aac..3a563ec1e8 100644
--- a/Modules/IGTUI/Qmitk/QmitkNavigationToolManagementWidget.cpp
+++ b/Modules/IGTUI/Qmitk/QmitkNavigationToolManagementWidget.cpp
@@ -1,317 +1,323 @@
 /*=========================================================================
 
 Program:   Medical Imaging & Interaction Toolkit
 Language:  C++
 Date:      $Date: 2009-05-12 19:14:45 +0200 (Di, 12 Mai 2009) $
 Version:   $Revision: 1.12 $
 
 Copyright (c) German Cancer Research Center, Division of Medical and
 Biological Informatics. All rights reserved.
 See MITKCopyright.txt or http://www.mitk.org/copyright.html for details.
 
 This software is distributed WITHOUT ANY WARRANTY; without even
 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 PURPOSE.  See the above copyright notices for more information.
 
 =========================================================================*/
 
 #include "QmitkNavigationToolManagementWidget.h"
 
 //mitk headers
 #include "mitkTrackingTypes.h"
 #include <mitkSTLFileReader.h>
 #include <mitkSurface.h>
 #include <mitkNavigationToolReader.h>
 #include <mitkNavigationToolWriter.h>
 #include <mitkNavigationToolStorage.h>
 #include <mitkNavigationToolStorageDeserializer.h>
 #include <mitkNavigationToolStorageSerializer.h>
 
 //qt headers
 #include <qfiledialog.h>
 #include <qmessagebox.h>
 
 //poco headers
 #include <Poco/Path.h>
 
 const std::string QmitkNavigationToolManagementWidget::VIEW_ID = "org.mitk.views.navigationtoolmanagementwidget";
 
 QmitkNavigationToolManagementWidget::QmitkNavigationToolManagementWidget(QWidget* parent, Qt::WindowFlags f)
   : QWidget(parent, f)
 {
   m_Controls = NULL;
   CreateQtPartControl(this);
   CreateConnections();
   m_NavigationToolStorage = mitk::NavigationToolStorage::New();
   m_Controls->m_SurfaceChooser->SetAutoSelectNewItems(true);
 }
 
 
 QmitkNavigationToolManagementWidget::~QmitkNavigationToolManagementWidget()
 {
 }
 
 void QmitkNavigationToolManagementWidget::CreateQtPartControl(QWidget *parent)
   {
     if (!m_Controls)
     {
     // create GUI widgets
     m_Controls = new Ui::QmitkNavigationToolManagementWidgetControls;
     m_Controls->setupUi(parent);
     }
   }
 
 void QmitkNavigationToolManagementWidget::CreateConnections()
   {
     if ( m_Controls )
     {
       //main widget page:
       connect( (QObject*)(m_Controls->m_AddTool), SIGNAL(clicked()), this, SLOT(OnAddTool()) );
       connect( (QObject*)(m_Controls->m_DeleteTool), SIGNAL(clicked()), this, SLOT(OnDeleteTool()) );
       connect( (QObject*)(m_Controls->m_EditTool), SIGNAL(clicked()), this, SLOT(OnEditTool()) );
       connect( (QObject*)(m_Controls->m_LoadStorage), SIGNAL(clicked()), this, SLOT(OnLoadStorage()) );
       connect( (QObject*)(m_Controls->m_SaveStorage), SIGNAL(clicked()), this, SLOT(OnSaveStorage()) );
           
       //widget page "add tool":
       connect( (QObject*)(m_Controls->m_AddToolCancel), SIGNAL(clicked()), this, SLOT(OnAddToolCancel()) );
       connect( (QObject*)(m_Controls->m_AddToolSave), SIGNAL(clicked()), this, SLOT(OnAddToolSave()) );
       connect( (QObject*)(m_Controls->m_LoadSurface), SIGNAL(clicked()), this, SLOT(OnLoadSurface()) );
       connect( (QObject*)(m_Controls->m_LoadCalibrationFile), SIGNAL(clicked()), this, SLOT(OnLoadCalibrationFile()) );
     }
   }
 
 void QmitkNavigationToolManagementWidget::Initialize(mitk::DataStorage* dataStorage)
   {
   m_DataStorage = dataStorage;
   }
 
 //##################################################################################
 //############################## slots: main widget ################################
 //##################################################################################
 
 void QmitkNavigationToolManagementWidget::OnAddTool()
   {
     //initialize UI components
     m_Controls->m_SurfaceChooser->SetDataStorage(m_DataStorage);
     m_Controls->AddToolLabel->setText("<b>Add Tool:</b>");
     m_Controls->m_MainWidgets->setCurrentIndex(1);
 
     //reset input fields
     m_Controls->m_ToolNameEdit->setText("");
     m_Controls->m_IdentifierEdit->setText("NavigationTool#"+QString::number(m_NavigationToolStorage->GetToolCount()));
     m_Controls->m_SerialNumberEdit->setText("");
     m_Controls->m_CalibrationFileName->setText("");   
 
     m_edit = false;
   }
 
 void QmitkNavigationToolManagementWidget::OnDeleteTool()
   {
     //if no item is selected, show error message:
     if (m_Controls->m_ToolList->currentItem() == NULL) {MessageBox("Error: Please select tool first!");return;}
 
     m_DataStorage->Remove(m_NavigationToolStorage->GetTool(m_Controls->m_ToolList->currentIndex().row())->GetDataNode());
     m_NavigationToolStorage->DeleteTool(m_Controls->m_ToolList->currentIndex().row());
     UpdateToolTable();
 
   }
 
 void QmitkNavigationToolManagementWidget::OnEditTool()
   {
     //if no item is selected, show error message:
     if (m_Controls->m_ToolList->currentItem() == NULL) {MessageBox("Error: Please select tool first!");return;}
 
     //initialize UI components
     m_Controls->m_SurfaceChooser->SetDataStorage(m_DataStorage);
     m_Controls->AddToolLabel->setText("<b>Edit Tool:</b>");
     m_Controls->m_MainWidgets->setCurrentIndex(1);
 
     //fill forms
     mitk::NavigationTool::Pointer selectedTool = m_NavigationToolStorage->GetTool(m_Controls->m_ToolList->currentIndex().row());
     m_Controls->m_ToolNameEdit->setText(QString(selectedTool->GetDataNode()->GetName().c_str()));
     m_Controls->m_IdentifierEdit->setText(QString(selectedTool->GetIdentifier().c_str()));
     m_Controls->m_SerialNumberEdit->setText(QString(selectedTool->GetSerialNumber().c_str()));
     switch(selectedTool->GetTrackingDeviceType())
       {
       case mitk::NDIAurora:
               m_Controls->m_TrackingDeviceTypeChooser->setCurrentIndex(0);break;
       case mitk::NDIPolaris:
               m_Controls->m_TrackingDeviceTypeChooser->setCurrentIndex(1);break;
       case mitk::ClaronMicron:
               m_Controls->m_TrackingDeviceTypeChooser->setCurrentIndex(2);break;
       default:
               m_Controls->m_TrackingDeviceTypeChooser->setCurrentIndex(0);
       }
     m_Controls->m_CalibrationFileName->setText(QString(selectedTool->GetCalibrationFile().c_str()));
     switch(selectedTool->GetType())
       {
       case mitk::NavigationTool::Instrument:
         m_Controls->m_ToolTypeChooser->setCurrentIndex(0); break;
       case mitk::NavigationTool::Fiducial:
         m_Controls->m_ToolTypeChooser->setCurrentIndex(1); break;
       case mitk::NavigationTool::Skinmarker:
         m_Controls->m_ToolTypeChooser->setCurrentIndex(2); break;
       case mitk::NavigationTool::Unknown:
         m_Controls->m_ToolTypeChooser->setCurrentIndex(3); break;
       }
 
     m_Controls->m_SurfaceChooser->SetSelectedNode(selectedTool->GetDataNode());
     m_edit = true;
   }
 
 void QmitkNavigationToolManagementWidget::OnLoadStorage()
   {
     mitk::NavigationToolStorageDeserializer::Pointer myDeserializer = mitk::NavigationToolStorageDeserializer::New(m_DataStorage);
     std::string filename = QFileDialog::getOpenFileName(NULL,tr("Open Navigation Tool"), "/", "*.*").toAscii().data();
     if (filename == "") return;
     mitk::NavigationToolStorage::Pointer tempStorage = myDeserializer->Deserialize(filename);
     if (tempStorage.IsNull()) MessageBox("Error" + myDeserializer->GetErrorMessage());
     else 
       {
       m_NavigationToolStorage = tempStorage;
       Poco::Path myPath = Poco::Path(filename.c_str());
       m_Controls->m_StorageName->setText(myPath.getFileName().c_str());
       }
     UpdateToolTable();
   }
 
 void QmitkNavigationToolManagementWidget::OnSaveStorage()
   {
-    mitk::NavigationToolStorageSerializer::Pointer mySerializer = mitk::NavigationToolStorageSerializer::New();
+    //read in filename
     std::string filename = QFileDialog::getSaveFileName(NULL,tr("Save Navigation Tool"), "/", "*.*").toAscii().data();
-    if (!mySerializer->Serialize(filename,m_NavigationToolStorage)) MessageBox("Error: " + mySerializer->GetErrorMessage());
-    else 
+    if (filename == "") return; //canceled by the user
+   
+    //serialize tool storage
+    mitk::NavigationToolStorageSerializer::Pointer mySerializer = mitk::NavigationToolStorageSerializer::New();
+    if (!mySerializer->Serialize(filename,m_NavigationToolStorage)) 
       {
-      Poco::Path myPath = Poco::Path(filename.c_str());
-      m_Controls->m_StorageName->setText(myPath.getFileName().c_str());
+      MessageBox("Error: " + mySerializer->GetErrorMessage());
+      return;
       }
+    Poco::Path myPath = Poco::Path(filename.c_str());
+    m_Controls->m_StorageName->setText(myPath.getFileName().c_str());
+    
   }
 
 
 //##################################################################################
 //############################## slots: add tool widget ############################
 //##################################################################################
 
 void QmitkNavigationToolManagementWidget::OnAddToolSave()
   {
     mitk::NavigationTool::Pointer workTool;
    
     if (m_edit) //here we edit a existing tool
       {
       workTool = m_NavigationToolStorage->GetTool(m_Controls->m_ToolList->currentIndex().row());
       
       //edit existing DataNode...
       workTool->GetDataNode()->SetName(m_Controls->m_ToolNameEdit->text().toLatin1());
       workTool->GetDataNode()->SetData(m_Controls->m_SurfaceChooser->GetSelectedNode()->GetData());
       }
     else //here we create a new tool
       {
       workTool = mitk::NavigationTool::New();
     
       //create DataNode...
       mitk::DataNode::Pointer newNode = mitk::DataNode::New();
       newNode->SetName(m_Controls->m_ToolNameEdit->text().toLatin1());
       newNode->SetData(m_Controls->m_SurfaceChooser->GetSelectedNode()->GetData());
       m_DataStorage->Add(newNode);
       workTool->SetDataNode(newNode);
       }
 
     //fill NavigationTool object
     workTool->SetCalibrationFile(m_Controls->m_CalibrationFileName->text().toAscii().data());
     workTool->SetIdentifier(m_Controls->m_IdentifierEdit->text().toAscii().data());
     workTool->SetSerialNumber(m_Controls->m_SerialNumberEdit->text().toAscii().data());
     //Tracking Device
     if (m_Controls->m_TrackingDeviceTypeChooser->currentText()=="NDI Aurora") workTool->SetTrackingDeviceType(mitk::NDIAurora);
     else if (m_Controls->m_TrackingDeviceTypeChooser->currentText()=="NDI Polaris") workTool->SetTrackingDeviceType(mitk::NDIPolaris);
     else if (m_Controls->m_TrackingDeviceTypeChooser->currentText()=="Claron Technology Micron Tracker") workTool->SetTrackingDeviceType(mitk::ClaronMicron);
     else workTool->SetTrackingDeviceType(mitk::TrackingSystemNotSpecified);
     //ToolType
     if (m_Controls->m_ToolTypeChooser->currentText()=="Instrument") workTool->SetType(mitk::NavigationTool::Instrument);
     else if (m_Controls->m_ToolTypeChooser->currentText()=="Fiducial") workTool->SetType(mitk::NavigationTool::Fiducial);
     else if (m_Controls->m_ToolTypeChooser->currentText()=="Skinmarker") workTool->SetType(mitk::NavigationTool::Skinmarker);
     else workTool->SetType(mitk::NavigationTool::Unknown);
 
     if (!m_edit) m_NavigationToolStorage->AddTool(workTool);
 
     UpdateToolTable();
 
     m_Controls->m_MainWidgets->setCurrentIndex(0);
   }
 
 void QmitkNavigationToolManagementWidget::OnAddToolCancel()
   {
     m_Controls->m_MainWidgets->setCurrentIndex(0);
   }
 
 void QmitkNavigationToolManagementWidget::OnLoadSurface()
   {
     std::string filename = QFileDialog::getOpenFileName(NULL,tr("Open Surface"), "/", "*.stl").toLatin1().data();
     mitk::STLFileReader::Pointer stlReader = mitk::STLFileReader::New();
     try
       {
       stlReader->SetFileName( filename.c_str() );
       stlReader->Update();
       }
     catch (...)
       {
       }
 
     if ( stlReader->GetOutput() == NULL );
     else
       {
       mitk::DataNode::Pointer newNode = mitk::DataNode::New();
       newNode->SetName(filename);
       newNode->SetData(stlReader->GetOutput());
       m_DataStorage->Add(newNode);
       }
   }
 
 void QmitkNavigationToolManagementWidget::OnLoadCalibrationFile()
   {
     m_Controls->m_CalibrationFileName->setText(QFileDialog::getOpenFileName(NULL,tr("Open Calibration File"), "/", "*.*"));
   }
 
 
 
 //##################################################################################
 //############################## private help methods ##############################
 //##################################################################################
 void QmitkNavigationToolManagementWidget::UpdateToolTable()
   {
   m_Controls->m_ToolList->clear();
   for(int i=0; i<m_NavigationToolStorage->GetToolCount(); i++)
     {
       QString currentTool = "Tool" + QString::number(i) + ": " + QString(m_NavigationToolStorage->GetTool(i)->GetDataNode()->GetName().c_str())+ " ";
       switch (m_NavigationToolStorage->GetTool(i)->GetTrackingDeviceType())
         {
         case mitk::ClaronMicron:
               currentTool += "(MicronTracker/"; break;
         case mitk::NDIAurora:
               currentTool += "(NDI Aurora/"; break;
         case mitk::NDIPolaris:
               currentTool += "(NDI Polaris/"; break;
         default:
               currentTool += "(unknown tracking system/"; break;
         }
       switch (m_NavigationToolStorage->GetTool(i)->GetType())
         {
         case mitk::NavigationTool::Instrument:
               currentTool += "Instrument)"; break;
         case mitk::NavigationTool::Fiducial:
               currentTool += "Fiducial)"; break;
         case mitk::NavigationTool::Skinmarker:
               currentTool += "Skinmarker)"; break;
         default:
               currentTool += "Unknown)";
         }
       m_Controls->m_ToolList->addItem(currentTool);
     }
 
   }
 
 void QmitkNavigationToolManagementWidget::MessageBox(std::string s)
   {
   QMessageBox msgBox;
   msgBox.setText(s.c_str());
   msgBox.exec();
   }