Under regular function calling/returning in C and C++, if your don't ever want to return anything from a function, you define it's return type as void. For example, a function that takes no arguments, and returns nothing can be prototyped as:
void foo(void);
A common misconception is that the same logic can be applied to main(). Well, it can't, main() is special, you should always follow the standard and define the return type as int.
