How to define a variable and assign a variable

want to define and assign variable, however got error

when use variable
Error (10500): VHDL syntax error at LabT1.vhd(31) near text "variable"; expecting "end", or "(", or an identifier ("variable" is a reserved keyword), or a concurrent statement

when use generic
Error (10500): VHDL syntax error at LabT1.vhd(31) near text "generic"; expecting "end", or "(", or an identifier ("generic" is a reserved keyword), or a concurrent statement

other error
Error (10500): VHDL syntax error at LabT1.vhd(31) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(32) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(33) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(34) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(37) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(38) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(39) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(40) near text ":="; expecting ";", or "port", or "generic"
Error (10500): VHDL syntax error at LabT1.vhd(53) near text "<"; expecting "(", or an identifier, or unary operator
Error (10500): VHDL syntax error at LabT1.vhd(53) near text ";"; expecting "<="
Error (10500): VHDL syntax error at LabT1.vhd(54) near text ">"; expecting "(", or an identifier, or unary operator
Error (10500): VHDL syntax error at LabT1.vhd(55) near text ~
Error (10500): VHDL syntax error at LabT1.vhd(55) near text ">"; expecting "(", or an identifier, or unary operator
Error (10500): VHDL syntax error at LabT1.vhd(96) near text ":"; expecting ")", or ","
Error (10500): VHDL syntax error at LabT1.vhd(97) near text ":"; expecting ")", or ","
Error (10500): VHDL syntax error at LabT1.vhd(116) near text "/"; expecting "end", or "(", or an identifier, or a sequential statement
Error (10500): VHDL syntax error at LabT1.vhd(117) near text "/"; expecting "end", or "(", or an identifier, or a sequential statement
Error (10500): VHDL syntax error at LabT1.vhd(118) near text "/"; expecting "end", or "(", or an identifier, or a sequential statement




LIBRARY ieee;
USE ieee.std_logic_1164.all;


ENTITY LabT1 IS
PORT ( SW : IN STD_LOGIC_VECTOR(17 DOWNTO 0);
LEDR : OUT STD_LOGIC_VECTOR(17 DOWNTO 0);
--Input
CLOCK_50 : IN STD_LOGIC;
--ENET0_INT_N
--ENET0_LINK100
ENET0_RX_CLK : IN STD_LOGIC;
--ENET0_RX_COL
--ENET0_RX_CRS
ENET0_RX_DATA : IN STD_LOGIC_VECTOR(3 DOWNTO 0);
--ENET0_RX_DV
--ENET0_RX_ER
ENET0_TX_CLK : IN STD_LOGIC;
--Output
ENET0_GTX_CLK : OUT STD_LOGIC;
--ENET0_MDC
--ENET0_RST_N
ENET0_TX_DATA : OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
ENET0_TX_EN : OUT STD_LOGIC
--ENET0_TX_ER
);


END LabT1;


ARCHITECTURE Behavior OF LabT1 IS
BEGIN
variable IPsource_1 : integer := 192;
variable IPsource_2 : integer := 168;
variable IPsource_3 : integer := 0;
variable IPsource_4 : integer := 5;


--"IP destination" - put the IP of the PC you want to send to
variable IPdestination_1 : integer := 192;
variable IPdestination_2 : integer := 168;
variable IPdestination_3 : integer := 0;
variable IPdestination_4 : integer := 1;


--"Physical Address" - put the address of the PC you want to send to
--10-78-D2-AD-90-CB
variable PhysicalAddress_1 := X"10";
variable PhysicalAddress_2 := X"78";
variable PhysicalAddress_3 := X"D2";
variable PhysicalAddress_4 := X"AD";
variable PhysicalAddress_5 := X"90";
variable PhysicalAddress_6 := X"CB";
-- we send a UDP packet, 18 bytes payload


-- calculate the IP checksum, big-endian style
variable IPchecksum1 = X"0000C53F" + (IPsource_1<<8)+IPsource_2+(IPsource_3<<8)+IPsourc e_4+(IPdestination_1<<8)+IPdestination_2+(IPdestin ation_3<<8)+(IPdestination_4);
variable IPchecksum2 = ((IPchecksum1 & X"0000FFFF")+(IPchecksum1>>16));
variable IPchecksum3 = ~((IPchecksum2 & X"0000FFFF")+(IPchecksum2>>16));


--reg [6:0] rdaddress;
--reg [7:0] pkt_data;
tx_process : process(CLOCK_50)
begin
if SW(0) = '1' then
h00: ENET0_TX_DATA <= X"55";
h01: ENET0_TX_DATA <= X"55";
h02: ENET0_TX_DATA <= X"55";
h03: ENET0_TX_DATA <= X"55";
h04: ENET0_TX_DATA <= X"55";
h05: ENET0_TX_DATA <= X"55";
h06: ENET0_TX_DATA <= X"55";
h07: ENET0_TX_DATA <= X"D5";
--Ethernet header
h08: ENET0_TX_DATA <= PhysicalAddress_1;
h09: ENET0_TX_DATA <= PhysicalAddress_2;
h0A: ENET0_TX_DATA <= PhysicalAddress_3;
h0B: ENET0_TX_DATA <= PhysicalAddress_4;
h0C: ENET0_TX_DATA <= PhysicalAddress_5;
h0D: ENET0_TX_DATA <= PhysicalAddress_6;
h0E: ENET0_TX_DATA <= X"00";
h0F: ENET0_TX_DATA <= X"12";
h10: ENET0_TX_DATA <= X"34";
h11: ENET0_TX_DATA <= X"56";
h12: ENET0_TX_DATA <= X"78";
h13: ENET0_TX_DATA <= X"90";
--IP header
h14: ENET0_TX_DATA <= X"08";
h15: ENET0_TX_DATA <= X"00";
h16: ENET0_TX_DATA <= X"45";
h17: ENET0_TX_DATA <= X"00";
h18: ENET0_TX_DATA <= X"00";
h19: ENET0_TX_DATA <= X"2E";
h1A: ENET0_TX_DATA <= X"00";
h1B: ENET0_TX_DATA <= X"00";
h1C: ENET0_TX_DATA <= X"00";
h1D: ENET0_TX_DATA <= X"00";
h1E: ENET0_TX_DATA <= X"80";
h1F: ENET0_TX_DATA <= X"11";
h20: ENET0_TX_DATA <= IPchecksum3(15:8);
h21: ENET0_TX_DATA <= IPchecksum3(7:0);
h22: ENET0_TX_DATA <= IPsource_1;
h23: ENET0_TX_DATA <= IPsource_2;
h24: ENET0_TX_DATA <= IPsource_3;
h25: ENET0_TX_DATA <= IPsource_4;
h26: ENET0_TX_DATA <= IPdestination_1;
h27: ENET0_TX_DATA <= IPdestination_2;
h28: ENET0_TX_DATA <= IPdestination_3;
h29: ENET0_TX_DATA <= IPdestination_4;
--UDP header
h2A: ENET0_TX_DATA <= X"04";
h2B: ENET0_TX_DATA <= X"00";
h2C: ENET0_TX_DATA <= X"04";
h2D: ENET0_TX_DATA <= X"00";
h2E: ENET0_TX_DATA <= X"00";
h2F: ENET0_TX_DATA <= X"1A";
h30: ENET0_TX_DATA <= X"00";
h31: ENET0_TX_DATA <= X"00";
--payload
h32: ENET0_TX_DATA <= X"00"; // put here the data that you want to send
h33: ENET0_TX_DATA <= X"01"; // put here the data that you want to send
h34: ENET0_TX_DATA <= X"02"; // put here the data that you want to send
h35: ENET0_TX_DATA <= X"03"; // put here the data that you want to send
h36: ENET0_TX_DATA <= X"04"; // put here the data that you want to send
h37: ENET0_TX_DATA <= X"05"; // put here the data that you want to send
h38: ENET0_TX_DATA <= X"06"; // put here the data that you want to send
h39: ENET0_TX_DATA <= X"07"; // put here the data that you want to send
h3A: ENET0_TX_DATA <= X"08"; // put here the data that you want to send
h3B: ENET0_TX_DATA <= X"09"; // put here the data that you want to send
h3C: ENET0_TX_DATA <= X"0A"; // put here the data that you want to send
h3D: ENET0_TX_DATA <= X"0B"; // put here the data that you want to send
h3E: ENET0_TX_DATA <= X"0C"; // put here the data that you want to send
h3F: ENET0_TX_DATA <= X"0D"; // put here the data that you want to send
h40: ENET0_TX_DATA <= X"0E"; // put here the data that you want to send
h41: pkt_data <= X"0F"; // put here the data that you want to send
h42: pkt_data <= X"10"; // put here the data that you want to send
h43: pkt_data <= X"11"; // put here the data that you want to send
default: pkt_data <= X"00";


end if;
end process tx_process;
END Behavior;