it gives me the error 'implicit declaration of function getchar(...)'what does it mean?Code:#include <conio.h> #include <iostream.h> int prime(int n) { int i; if (n % 2 == 0) return (n==2); if (n % 3 == 0) return (n==3); if (n % 5 == 0) return (n==5); for (i=7; i*i <= n; i+=2) if (n % i == 0) return 0; return 1; } void main(void) { int i, n; n = 1000; clrscr(); cout << "ENTER THE NUMBER :-"; cin >> i; if (prime(i)) cout <<"\n THE NUMBER IS PRIME."; else cout << "\nTHE NUMBER IS NOT PRIME."; getch(); }