private void openExperiment() {
    
    int returnVal = m_FileChooser.showOpenDialog(this);
    if (returnVal != JFileChooser.APPROVE_OPTION) {
      return;
    }
    File expFile = m_FileChooser.getSelectedFile();
    
    // add extension if necessary
    if (m_FileChooser.getFileFilter() == m_ExpFilter) {
      if (!expFile.getName().toLowerCase().endsWith(Experiment.FILE_EXTENSION))
        expFile = new File(expFile.getParent(), expFile.getName() + Experiment.FILE_EXTENSION);
    }
    else if (m_FileChooser.getFileFilter() == m_KOMLFilter) {
      if (!expFile.getName().toLowerCase().endsWith(KOML.FILE_EXTENSION))
        expFile = new File(expFile.getParent(), expFile.getName() + KOML.FILE_EXTENSION);
    }
    else if (m_FileChooser.getFileFilter() == m_XMLFilter) {
      if (!expFile.getName().toLowerCase().endsWith(".xml"))
        expFile = new File(expFile.getParent(), expFile.getName() + ".xml");
    }
    
    try {
      Experiment exp = Experiment.read(expFile.getAbsolutePath());
      setExperiment(exp);
      System.err.println("Opened experiment:\n" + m_Exp);
    } catch (Exception ex) {
      ex.printStackTrace();
      JOptionPane.showMessageDialog(this, "Couldn't open experiment file:\n"
				    + expFile
				    + "\nReason:\n" + ex.getMessage(),
				    "Open Experiment",
				    JOptionPane.ERROR_MESSAGE);
      // Pop up error dialog
    }
  }