public void update_key()
	{	
		if(isReadOnly()) return;
		
		if(Idx!=null)
			{
			PREPARE_KEY_FROM_DATA( Idx );
			if(cSKey==null || (!cSKey.equals(Idx.searchKey)))
				Idx.replace_key();	// this is a hack too much
			}
		if(cdx_file)
			{
			// TODO:
			// update all key values for this record for all tags
			}
	}