if statment issue

I am trying to build a 4x4 cross bar which i will use in a switch datapth. Here is the cross bar code:

library ieee;

use ieee.std_logic_1164.all;

entity cross_bar is

port(

-- clk,rst : in std_logic;

din0,din1,din2,din3 : in std_logic_vector(34 downto 0);

grant0,grant1,grant2,grant3 : in std_logic_vector(1 downto 0);

dout0,dout1,dout2,dout3 : out std_logic_vector(34 downto 0)

-- req0,req1,req2,req3 : out std_logic_vector(1 downto 0)

);

end cross_bar;

architecture cross_arc of cross_bar is

begin

process

begin

if (din0(din0'length-1 downto 32) = "00") then

if (grant0 = "00") then

dout0 <= din0;

elseif (grant1 = "01") then

dout1 <= din0;

elseif (grant2 = "10") then

dout2 <= din0;

else (grant3 = "11") then

dout3 <= din0;

end if;

end if;

end process;

end cross_arc;

I am mad. Cant figure it out from last 2 hours. :(