fundtion work
( 
    player_x  	pl,
    coord3d  	pos,
    int  	keys 
){
    local s3 = ["N", "0", "P"];
    local s6 = ["N", "n", "-", "+", "p", "P"];
    local row = settings.get_station_coverage();
    local spacing = 2+2*settings.get_station_coverage();
    // The first 2 could be 1 in paks which have on-road stations that 
    // can handle both passengers and mail.
    foreach (prow in s3)
    {
        foreach (trow in s3)
        {
            foreach (hrow in s6)
            {
                local col = settings.get_station_coverage();
                foreach (pcol in s3)
                {
                    foreach (tcol in s3)
                    {
                        foreach (hcol in s6)
                        {

			    local tile = square_x(col, row).get_ground_tile();
                            label_x.create(tile player,
				prow+pcol+trow+tcol+hrow+hcol);
			    mark_tile(tile);
                            col+=spacing;
                        }
                    }
                }
                row += spacing;
            }
        }
    }
}