I am doing my project and it doesn't work in the simulation...
I found it might be caused by g_register and register...
A programmer said that g means global, is it right?
Could anyone give me example?
Thanks a lot! 
What simulation are you talking about?
it's very long if I should explain what the simulation is all about...
Hmmm, how I could explain this....
I am using PROTEUS ISIS for the arduino simulation...
Yeah, that doesn't help. What simulation are you talking about? You need to add some useful context to get an answer.
I am making a counter to count the amount of cable production...
the counter display is 3 lines of 7segment...each lines contain 4 7seg,means maximum to 9999...
I hope it helps....
creativen:
A programmer said that g means global, is it right?
What programmer?
C++ and Java programmer...
He is undergraduate in Bachelor of Computing....
Have you tried it on a real Arduino, using the Arduino IDE?
What is this "it" of which you speak? I'm not at all clear what he is doing.
Neither am I, but until it gets out of the pretend world of a simulator and whatever compiler is being used (if it isn't the Arduino IDE), I think it's out of scope for this forum.
I am making a counter to count the amount of cable production...
the counter display is 3 lines of 7segment...each lines contain 4 7seg,means maximum to 9999...
It's not like it would need a lot of hardware to try it out.