private void updatePreferences(IEclipsePreferences preferences) {
IEclipsePreferences oldPreferences = loadPreferences();
if (oldPreferences != null) {
try {
String[] propertyNames = oldPreferences.childrenNames();
for (int i = 0; i < propertyNames.length; i++){
String propertyName = propertyNames[i];
String propertyValue = oldPreferences.get(propertyName, ""); //$NON-NLS-1$
if (!"".equals(propertyValue)) { //$NON-NLS-1$
preferences.put(propertyName, propertyValue);