find the factorial of a number by tail recursive method

/*P5.14 Program to find the factorial of a number by tail recursive method*/

#include<stdio.h>
long TailRecursiveFact(int n);
long TRfact(int n, int result);
main( )
{
    int num;
    printf("Enter a number : ");
    scanf("%d", &num);
    if(num<0)
        printf("No factorial for negative number\n");
    printf("Factorial of %d is %ld\n", num, TailRecursiveFact(num) );
}

/*Tail recursive*/
long TRfact(int n, int result)
{
    if( n==0)
        return result;
    return TRfact(n-1, n*result);
}/*End of TRFact()*/

/*Helper function for tail recursive function*/
long TailRecursiveFact(int n)
{
    return TRfact(n, 1);
}/*End of TailRecursiveFact()*/