#include <stdio.h>

char GetALetter(); 
void PrintQuotient(int x, int y); 
void KillSomeTime();  

int main()
{
   char result;

   result = GetALetter();	// no parameters, but returns a char

   PrintQuotient(9, 5);		// void function.  call by itself
   PrintQuotient(5, 0);

   printf("Before KillSomeTime() is called\n");
   KillSomeTime();
   printf("After KillSomeTime() is called\n");

   return 0;
}

char GetALetter()
{
  int isLetter;
  char let;
  do
  {
    printf("Please enter a letter of the alphabet: ");
    scanf(" %c", &let);

    isLetter = (let >= 'A' && let <= 'Z') || (let >= 'a' && let <= 'z');

    if (!isLetter)
 	printf("Not a letter.  Try again.\n");

  } while (!isLetter);

  return let;
}


void PrintQuotient(int x, int y)
{
   if (y == 0)
   {
      printf("I'm not going to divide by 0 !\n");
      return;
   } 

   printf("The quotient of %d divided by %d is: %d\n", x, y, (x / y) ); 
}

void KillSomeTime()
// this function is going to just delay a little
{
   int x = 0, y;

   while (x < 1000000000)
   {
      y = x * x;
      x++;
   }

}