Thread: Force end

Is there any way to force a program to shut down without using code to make it crash (or using a while loop)? If the answer is in a tutorial on this site, please tell me which tutorial and I'll find it myself. The reason I want this is to shut down the program when it fails to load a file, preventing the program from screwing up by calling data from a file that doesnt exist, or is corrupted, damaged etc. If there isn't any way to do this please tell me. I'll use the while loop if I have to, but I thought there might be a quicker and easier way to do it.
EDIT: I have another problem. I just wrote this switch-case bit and Dev C++ is telling my that there are undeclared functions (n, l, and y)

Code:

 
cout<<"Would you like to create a new data file or load an existing one.\n";
cout<<"[N]ew or [L]oad (Capitalized)\n";
cin>> newload;
cin.ignore();
switch ( newload ) {
case n:
  cout<<"Are you sure? Saved data will be Erased.\n";
  cout<<"[Y]es or [N]o (Capitalized)\n";
  cin>> sure;
  cin.ignore();
    switch ( sure ) {
    case y:
      break;
    case n:
//This is where i want to put the "End program" statement if I can
      break;
    default:
      break;
    }
  break;
case l:
  break;
default:
  break;
}

I havent actually put in the code between the case and break sections yet, but as far as I can tell, I don't have any errors in it. I'm also getting a "Warning: Unreachable code at beginning of switch statement" error that I don't understand. I know it's a lot of questions, but I can't find my error, so I need help. Yes, I did check the Switch-Case tutorial but as far as I can tell, I haven't made an error.