Thank you guys for helping me out, you are real kind person !

Just to summarize :

Org 0000h
LJMP andy ;due to "too short"
;routine before I
;hit interrupt
:routine

org 0100h
andy: start my code here

I hope I can it right here ! If not, so sorry to trouble you guys out here !

Thanks a million in advance !

Have a nice day !

Best Regards
Andy (Singapore)