Thanks so much for the answer reneeb.

But as I stated in my 2nd posting of this thread. We don't need both. Namely, we don't even need "seek" function at all,
if we put "open INFILE.." within for-loop. It will work, that I know.

Forgive me if I sound nitpicking. But I just wonder if we can do
something by keeping "open" function outside for-loop,
while maintaining "seek" within? Would it be more efficient?