sram read and write

i am trying to alter the data stored(by control panel) in sram .i wrote the vhdl program to alter the data and i am reading with control panel to see if it is changed...my problem is every time i am reading only "1" on the data pins...i learnt that before reading the datawe need to put the biderectional data pins in high impedance state.i tried that also...my program is

LIBRARY ieee ;

USE ieee.std_logic_1164.all ;

use IEEE.std_logic_unsigned.all;

entity abc is

port(clk:in std_logic; --Input from FPGA switches

din:inout std_logic_vector(15 downto 0); -- Data outputs/inputs from/to SRAM from/to FPGA

ceo,oeo,weo,lbo,ubo:out std_logic; --Inputs to SRAM from FPGA

addr:out std_logic_vector(17 downto 0)-- Address inputs to SRAM from FPGA

);

end;

architecture abcd of abc is

begin

ceo <= '0';

oeo <= '0';

lbo <= '0';

ubo <= '0';

process(clk)

variable temp_addr:std_logic_vector(17 downto 0) :="000010101011001010" ;

variable temporary: std_logic_vector(15 downto 0);

variable count,flg:integer range 0 to 100:=0;

begin

if clk'event and clk = '1' then

if (count<=10) then

if flg = 0 then

flg:= 1;

end if;

if flg = 1 then

din <= (others => 'Z');

addr <= temp_addr;

weo <= '1';

temporary := din;

flg := 2;

end if;

if flg = 2 then

temp_addr:=temp_addr+1;

weo<='0';

din <= temporary and x"10ff" ;

flg := 0;

count := count+1;

end if;

end if;

end if;

end process;

end;

can anybody please help me find the problem