code: public final static int createLocalId()
  	{
  		Storage storage = Storage.getLocalStorageIfSupported();
  		if( storage == null )
  			return 0;
  
  		int increment = 0;
  		String incrementString = storage.getItem( LOCAL_CURRENT_ID_INCREMENT );
  		try
  		{
  			increment = Integer.parseInt( incrementString );
  		}
  		catch( Exception e )
  		{
  		}
  
  		increment += 1;
  
  		storage.setItem( LOCAL_CURRENT_ID_INCREMENT, increment + "" );
  
  		return -increment;
  	}
docs: Create a negative ID.