Program that outputs twin prime numbers

I need to write a code that has you input a number and it checks that the given number is a twin prime with the prime number that follows it. Here is what I have so far:

int isPrime (int Value){
    int Number;
        for (Number=2; Number <= Value-1; Number++){
        if (Value % Number ==0)
            return 0;
        else
            return 1;
}
}
int nextPrime(int current){
    while (1){
    if (isPrime(current))
        return current;
        current++;
    }
}
int main(){
    int a;
    int First = nextPrime (a);
    int Second = nextPrime(First + 1);
    scanf("%d", &a);
    if (Second - First == 2) {
        printf("%d and %d are twin primes.", First, Second);
    } else {
        printf("%d and %d are not twin primes.", First, Second);
    }
    return 0;
}