can you find the small error for me,sir............ :(

this is the time to show in LCD. i cannot find the problem. i want to show hour for 01-12. but its also include 00. so after 12hr it become 00hr and then 01 hr. that is the wrong. can u find the error, sir. plz help me. that is very important for me ................. thank sir

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity counter_up is

Port ( clk : in STD_LOGIC;

SET : in STD_LOGIC;

BTN0 : in STD_LOGIC;

BTN1 : in STD_LOGIC;

BTN2 : in STD_LOGIC;

BTN3 : in STD_LOGIC;

BTN4 : in STD_LOGIC;

BTN5 : in STD_LOGIC;

reset : in STD_LOGIC;

AM : out STD_LOGIC;

hex0 : out STD_LOGIC_VECTOR (3 downto 0);

hex1 : out STD_LOGIC_VECTOR (3 downto 0);

hex2 : out STD_LOGIC_VECTOR (3 downto 0);

hex3 : out STD_LOGIC_VECTOR (3 downto 0);

hex4 : out STD_LOGIC_VECTOR (3 downto 0);

hex5 : out STD_LOGIC_VECTOR (3 downto 0));

end counter_up;

architecture Behavioral of counter_up is

signal count0:std_logic_vector(3 downto 0):=(others=>'0');

signal count1:std_logic_vector(3 downto 0):=(others=>'0');

signal count2:std_logic_vector(3 downto 0):=(others=>'0');

signal count3:std_logic_vector(3 downto 0):=(others=>'0');

signal count4:std_logic_vector(3 downto 0):=x"1";

signal reg:std_logic:='0';

begin

process(clk,reset)

begin

if reset='1' then

count0<=(others=>'0');

count1<=(others=>'0');

count2<=(others=>'0');

count3<=(others=>'0');

count4<=x"1";

elsif rising_edge(clk) then

if SET='1' then

if (count0=x"9" and BTN0='1') then

count0<=x"0";

elsif (BTN0='1') then

count0<=count0+1;

elsif (count1=x"5" and BTN1='1') then

count1<=x"0";

elsif (BTN1='1') then

count1<=count1+1;

elsif (count2=x"9" and BTN2='1') then

count2<=x"0";

elsif (BTN2='1') then

count2<=count2+1;

elsif (count3=x"5" and BTN3='1') then

count3<=x"0";

elsif (BTN3='1') then

count3<=count3+1;

elsif (count4=x"C" and BTN4='1') then

count4<=x"1";

elsif (BTN4='1') then

count4<=count4+1;

elsif(BTN5='1') then

reg<=not(reg);

end if;

else

if (count4=x"C" and count3=x"5" and count2=x"9" and count1=x"5" and count0=x"9") then

reg<=not(reg);

count0<=(others=>'0');

count1<=(others=>'0');

count2<=(others=>'0');

count3<=(others=>'0');

count4<= x"1";

elsif (count3=x"5" and count2=x"9" and count1=x"5" and count0=x"9") then

count0<=(others=>'0');

count1<=(others=>'0');

count2<=(others=>'0');

count3<=(others=>'0');

count4<=count4 + 1;

elsif (count2=x"9" and count1=x"5" and count0=x"9") then

count0<=(others=>'0');

count1<=(others=>'0');

count2<=(others=>'0');

count3<=count3 + 1;

elsif (count1=x"5" and count0=x"9") then

count0<=(others=>'0');

count1<=(others=>'0');

count2<=count2 + 1;

elsif (count0=x"9") then

count0<=(others=>'0');

count1<=count1 + 1;

else

count0<=count0 + 1;

end if;

end if;

end if;

end process;

AM <= reg;

hex0<=count0;

hex1<=count1;

hex2<=count2;

hex3<=count3;

hex4<=

count4 when (count4<x"A") else

"00"&count4(2 downto 1) when count4=x"C" else

"00"&count4(0);

hex5<=

"0001" when (count4=x"A" or count4=x"B" or count4=x"C") else

"0000";

end Behavioral;