matrix generation

Hi there,
i have some problem. I need to get sorting net. 40 comparators in 81
line.

First i declared matrix:

        type wire is array (0 to 81) of std_logic_vector (7 downto 0);
        type connections is array (0 to 81) of wire;

Then i'm trying to generate a net of comparators.

component comparator
        port(
        clk : in std_logic;
        rst : in std_logic;

   A_in : in std_logic_vector (7 downto 0);
        B_in : in std_logic_vector (7 downto 0);

        A_out : out std_logic_vector (7 downto 0);
        B_out : out std_logic_vector (7 downto 0)
);
end component;

sorting_net : for i in 0 to 40 generate
        ins: for j in (0 to 81) generate
                comparatorx : comparator port map(clk, rst, connections(i*2) of
wire(j), connections(i*2 + 1) of wire (j), connections(i*2) of wire (j
+1), connections(i*2 + 1) of wire (j+1));
        end generate;
end generate;

And after that i get few errors. I use quartus.
Anyone could help me?

best wishes,
Damian