Sorting a linked list based on variable C

void sortedInsert(struct listelement** list_ptr, struct listelement* newNode)
{
    struct listelement* temp;

    while (((temp = *list_ptr) &&
           (temp->surveyDetails.ppsNo < newNode->surveyDetails.ppsNo))) {
        list_ptr = &temp->next;
    }

    newNode->next = temp;
    *list_ptr = newNode;
}

void addElement(struct listelement** list_ptr)
{
    int inputPPS;
    struct listelement *list;
    struct listelement *newNode;

    list = *list_ptr;
    newNode = malloc(sizeof *newNode);

    if (list == NULL) {
        printf("\nWe will now take details from you for the survery...\n");
    }

    // keep asking for a PPS number, until we get a unique one
    while (1) {
        printf("\nPlease enter your PPS number (Number must be unique):");
        scanf("%d", &inputPPS);
        if (checkUnique(list, inputPPS)) {
            break;
        }
        printf("\nWe still value your feedback on this topic! If you believe you have entered your PPS incorrectly you can now try again!");
    }

    newNode->surveyDetails.ppsNo = inputPPS;
    printf("\nPlease enter your first name:");
    scanf("%*s", sizeof(newNode->surveyDetails.fName), newNode->surveyDetails.fName);
    printf("\nPlease enter your last name:");
    scanf("%*s", sizeof(newNode->surveyDetails.lName), newNode->surveyDetails.lName);
    //printf("\nEnter email address: ");
    //do email validation
    //scanf("%*s", sizeof(newNode->studentData.email), newNode->studentData.email);

    printf("\nEnter current address:");
    scanf("%*s", sizeof(newNode->surveyDetails.address), newNode->surveyDetails.address);

    printf("\nPlease enter your age:");
    scanf("%d", &newNode->surveyDetails.age);
    printf("\nPlease enter your yearly salary (as whole number):");
    scanf("%d", &newNode->surveyDetails.income);
    printf("\nHow many cigarrettes do you smoke a day? :");
    scanf("%d", &newNode->surveyDetails.ciggiesSmoked);
    printf("\nHow many units of alcohol do you drink in a day? :");
    scanf("%d", &newNode->surveyDetails.unitsTaken);
    printf("\nHow many time do you exercise every week? :");
    scanf("%d", &newNode->surveyDetails.timesExercised);

    sortedInsert(list_ptr, newNode);
    printf("\nSurvey stored successfully\n");
}

int checkUnique(struct listelement *list, int ppsNo)
{
    struct listelement *temp;

    for (temp = list; temp; temp = temp->next) {
        if (temp->surveyDetails.ppsNo == ppsNo) {
            printf("\n There is a user in the survey system with this PPS Number.");
            return 0;
        }
        else if (temp->surveyDetails.ppsNo > ppsNo) {
            // the list is sorted, so if we find an element with a pps greater than
            // the one we're looking for, then we need look no further
            break;
        }
    }

    printf("\nPPS Number is unique. Continuing...\n We will now ask you for your survey details... ");

    return 1;
}