void hideBorderX(int y1, int y2, int x)
    {
        int ylow, yhigh;

        if (y1 < y2)
        {
            ylow  = y1;
            yhigh = y2;
        }
        else
        {
            ylow  = y2;
            yhigh = y1;
        }
        TileSelect north = (TileSelect)MapTiles[x, yhigh].GetComponent <TileSelect>();
        TileSelect south = (TileSelect)MapTiles[x, ylow].GetComponent <TileSelect>();

        if (north.borderOcclusion && south.borderOcclusion)
        {
            north.HideSouth();
            south.HideNorth();
        }
    }