prime numbers

#include <stdio.h>
#include <stdlib.h>

int isPrime (unsigned long value);

int main (void)
{
    int i;

    for (i = 2; i <= 80000; i++)
        if (isPrime(i))
            printf("%d\n", i);

    system("pause > nul");
    return 0;
}

int isPrime (unsigned long value)
{
    unsigned long i;
    if (value <= 1)
        return 0;

    for (i = 2; i < value / 2 + 1; i++)
        if ((value % i) == 0)
            return 0;

    return 1;
}