Function- No Return With Argument Passing

/*   No Return No Argument Passing
*/

 #include<stdio.h>
 #include<conio.h>

  void main ()
 {
     clrscr();

     void square(void); // Prototype or declaration

      printf("** This Program Will Demonstrate the No Return No Argument"
		 "based Function  ** \n");
	 square();// Calling Of Function

	 printf(" You have just seen the Square of a No.\n "
		"   Enter Any Key To Exit ");
	 getch();
  }

  void square(void)  // called function

  {

      int a;
      printf("\nPlease Enter a No. Whose Square You Want to Calculate:  ");
      scanf("%d",&a);
      printf("The square of %d is %d\n\n",a,a*a);

  }
  

Output