Dear Mr Geert Vancompernolle

Thank you very much,

I have tried your suggesstion,
and It solved the problem.

At first, It works fine on simulator.
Then, when it was tried with Hyperterminal
the problem still the same as when it was
tried with my own program.

But after your suggestion
is considered, the Interrupt could be fixed.

Again thank you very much.
Thank's for others too.