Sql Trigger Not Working

i am having an issue with my trigger code
i believe that i should be able to use the multiple if else statements
and i just threw in an update in each begin end statement
but when i check the syntax it fails

any reason why that is
CREATE TRIGGER [tr_update_conveyor_interface] ON [dbo].[t_conveyor_interface]
FOR UPDATE
AS


declare
@id integer,
@barcode varchar(25),
@epc_tag varchar(24),
@reject_flag char(1),
@hold_flag char(1),
@pe_3_flag char(1),
@old_id integer,
@old_barcode varchar(25),
@old_epc_tag varchar(24),
@old_reject_flag char(1),
@old_hold_flag char(1),
@old_pe_3_flag char(1)

select @barcode = c.barcode,
@id = c.id,
@epc_tag = c.epc_tag,
@reject_flag = c.reject_flag,
@hold_flag = c.hold_flag,
@pe_3_flag = c.pe_3_flag
from t_conveyor_interface c
inner join deleted d
on c.barcode = d.barcode

select @old_barcode = c.barcode,
@old_id = c.id,
@old_epc_tag = c.epc_tag,
@old_reject_flag = c.reject_flag,
@old_hold_flag = c.hold_flag,
@old_pe_3_flag = c.pe_3_flag
from t_conveyor_interface c
inner join inserted i
on c.barcode = i.barcode

if(@old_epc_tag <> @epc_tag)
begin
update t_load_audit
set id = 1
end

else
if(@old_reject_flag <> @reject_flag)
begin
update t_load_audit
set id = 1
end

else
if(@old_hold_flag <> @hold_flag)
begin
update t_load_audit
set id = 1
end

else
if(@old_pe_3_flag <> @pe_3_flag
begin
update t_load_audit
set id = 1
end