C Program to print the ascii equivalent of all chararters in the entered string

#include <stdio.h>
#include <conio.h>
#include <ctype.h>
int ascii_value(char c);
void main()
{

 int i,a;
 char c;
 clrscr();
 printf("Please enter a string.");
 printf(" String will be terminated if you press Ctrl-Z.");
 printf(" STRING:-  ");
 for (i=0;(c=getchar())!=EOF;i++)
 {
  a=ascii_value(c);
  printf("%d%c",a,' ');
 }
 printf("     are the ascii values of the characters of the entered string");
 printf("     respectively.");

 getch();
}

 int ascii_value(char c)
 {
  int a;
  a=(int)c;
  return(a);
 }