private static boolean isLayerName( String shortName )
    {
        int top = 0;
        int bot = layerNames.length-1;
        while ( top <= bot )
        {
            int mid = (top+bot)/2;
            int res = shortName.compareTo(layerNames[mid]);
            if ( res == 0 )
                return true;
            else if ( res < 0 )
                bot = mid-1;
            else
                top = mid+1;
        }
        return false;
    }