not running program while power on after sametime

Using Arduino Programming Questions
1

i have code about sim900 gsm module with arduino uno.
when i program the code, it is working properly.
after sometime when i power On the system, it is not working. i have to put the code again and again due to this problem.

pls give the answer for solve this problem,
thank you
pubudu

2

Post your program so we can see what you can see.

And please use the code button </>so your code looks like thisand is easy to copy to a text editor

...R