if not exists(SELECT column_name from sys.syscolumn sc join sys.systable st on sc.table_id = st.table_id 
where LCase(table_name) = LCase('Hotels') and LCase(column_name) = LCase('PayChislo')) then
  alter table Hotels
    add "PayChislo" integer default 0;
end if;

go

IF (EXISTS(Select * from sys.systrigger where LCase(trigger_name) = LCase('TrigHotelsPayChislo')))
THEN Drop trigger TrigHotelsPayChislo
END IF

GO

create trigger
TrigHotelsPayChislo after update order 3 on
DBA.Hotels
referencing new as HNEW old as HOLD
for each row
begin
  declare @HotelId integer;
  
  if (HNEW.PayChislo <> HOLD.PayChislo) then
    select IntStojnost into @HotelId from Registers where RegisterName='HotelID';
	if HNEW.Hotel_ID = @HotelId then
	  update Registers set IntStojnost = HNEW.PayChislo where RegisterName='PayChislo';
	  set bvrPayChislo = HNEW.PayChislo;
	end if;
  end if;
end

go