Using unions

/* 2005.c: Using unions */
#include <stdio.h>
#include <string.h>

struct survey {
char name[20];
char c_d_p;
int age;
int hour_per_week;
union {
char cable_company[16];
char dish_company[16];
} provider;
};

void DataEnter(struct survey *s);
void DataDisplay(struct survey *s);

main(void)
{
    struct survey tv;

    DataEnter(&tv);
    DataDisplay(&tv);

    return 0;
}
/* function definition */
void DataEnter(struct survey *ptr)
{
    char is_yes[4];

    printf("Are you using cable at home? (Yes or No)\n");
    gets(is_yes);
    if ((is_yes[0] == 'Y') || (is_yes[0] == 'y')){
        printf("Enter the cable company name:\n");
        gets(ptr->provider.cable_company);
        ptr->c_d_p = 'c';
    }
    else {
        printf("Are you using a satellite dish? (Yes or No)\n");
        gets(is_yes);
        if ((is_yes[0] == 'Y') || (is_yes[0] == 'y')){
            printf("Enter the satellite dish company name:\n");
            gets(ptr->provider.dish_company);
            ptr->c_d_p = 'd';
        }
        else {
            ptr->c_d_p = 'p';
        }
    }
    printf("Please enter your name:\n");
    gets(ptr->name);
    printf("Your age:\n");
    scanf("%d", &ptr->age);
    printf("How many hours you spend on watching TV per week:\n");
    scanf("%d", &ptr->hour_per_week);
}
/* function definition */
void DataDisplay(struct survey *ptr)
{
    printf("\nHere's what you've entered:\n");
    printf("Name: %s\n", ptr->name);
    printf("Age: %d\n", ptr->age);
    printf("Hour per week: %d\n", ptr->hour_per_week);
    if (ptr->c_d_p == 'c')
        printf("Your cable company is: %s\n",ptr->provider.cable_company);
    else if (ptr->c_d_p == 'd')
        printf("Your satellite dish company is: %s\n",ptr->provider.dish_company);
    else
        printf("You don't have cable or a satellite dish.\n");
        printf("\nThanks and Bye!\n");
}