Написал класс "Телефонная книга". Но при работе вылетает ошибка. помогите разобраться.

#include <iostream>
#include <string>
#define _DataBase "D:\\PhoneBook.txt"
#define _MAX_LEN 1000
 
using namespace std;
 
class PhoneBook
{
private:
    char *_Name;
    char *_Sur_Name;
    char *_PatroNymic;
    char *_Cell_Phone;
    char *_Home_Phone;
    char *_E_mail;
    char *_Home_Address;
public:
    PhoneBook();
    ~PhoneBook();
    int PhoneBook_Count(PhoneBook *obj, FILE *fp, char *_DBuff);
    void _Add_Data(PhoneBook *obj, FILE *fp, char *_TempBuff, char *_TStr);
    void _Delete_Data(PhoneBook *obj, FILE *fp, char *_DBuff);
    void _Display_Data(PhoneBook *obj, FILE *fp, char *_DBuff);
    void _Edit_data(PhoneBook *obj, FILE *fp, char *_DBuff);
    void _Menu_of_PhoneBook(PhoneBook *obj, FILE *fp, char *_DBuff, char *_TempBuff, char *_TStr, int choise);
    friend ostream & operator << (ostream &stream, PhoneBook obj);
};
 
int main ()
{
    FILE *fp = 0;
    char _DBuff[1000], _TempBuff[10], _TStr[50];
    int choise = 0;
    PhoneBook *obj = 0;
    obj = new PhoneBook();
    obj ->_Menu_of_PhoneBook(obj,fp,_DBuff,_TempBuff,_TStr,choise);
    delete obj;
    return 0;
}
PhoneBook::PhoneBook()
{
    this ->_Name = new char [_MAX_LEN];
    this ->_Sur_Name = new char [_MAX_LEN];
    this ->_PatroNymic = new char [_MAX_LEN];
    this ->_Cell_Phone = new char [_MAX_LEN];
    this ->_Home_Phone = new char [_MAX_LEN];
    this ->_E_mail = new char [_MAX_LEN];
    this ->_Home_Address = new char [_MAX_LEN];
}
PhoneBook::~PhoneBook()
{
    delete [] this ->_E_mail;
    delete [] this ->_Home_Phone;
    delete [] this ->_Cell_Phone;
    delete [] this ->_PatroNymic;
    delete [] this ->_Sur_Name;
    delete [] this ->_Name;
    delete [] this ->_Home_Address;
}
void PhoneBook::_Add_Data(PhoneBook *obj, FILE *fp, char *_TempBuff, char *_TStr)
{
    int Kol = 0;
    cout << "Enter the number of additions:" << endl;
    cin >> Kol;
    itoa(Kol,_TempBuff,10);
    gets(_TempBuff);
    for (int i = 0; i < Kol; i++)
    {
        if (fp = fopen(_DataBase, "a+"))
        {
            cout << "Enter the number of the order:" << endl; 
            gets(_TStr);
            strcat(_TStr, "\n");
            fputs(_TStr,fp);
 
            cout << "Enter a name:" << endl;
            gets(_Name);
            strcat(_Name, "\n");
            fputs(_Name,fp);
 
            cout << "Enter a surname:" << endl;
            gets(_Sur_Name);
            strcat(_Sur_Name, "\n");
            fputs(_Sur_Name,fp);
 
            cout << "Enter a first name:" << endl;
            gets(_PatroNymic);
            strcat(_PatroNymic, "\n");
            fputs(_PatroNymic,fp);
 
            cout << "Enter Enter your mobile phone:" << endl;
            gets(_Cell_Phone);
            strcat(_Cell_Phone, "\n");
            fputs(_Cell_Phone,fp);
 
            cout << "Enter Enter your home phone:" << endl;
            gets(_Home_Phone);
            strcat(_Home_Phone, "\n");
            fputs(_Home_Phone,fp);
 
            cout << "Enter Enter your E-mail adress:" << endl;
            gets(_E_mail);
            strcat(_E_mail, "\n");
            fputs(_E_mail,fp);
 
            cout << "Enter Enter your home address:" << endl;
            gets(_Home_Address);
            strcat(_Home_Address, "\n");
            fputs(_Home_Address,fp);
        }
        else
            cout << "Error opening file for writing." << endl;
    }
    fclose (fp);
    fp = 0;
}
void PhoneBook::_Delete_Data(PhoneBook *obj, FILE *fp, char *_DBuff)
{
 
}
void PhoneBook::_Display_Data(PhoneBook *obj, FILE *fp, char *_DBuff)
{
    if (fp = fopen (_DataBase, "r"))
    {
        fgets(_DBuff,1000,fp);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_Name,_DBuff);
        this ->_Name = char(0);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_Sur_Name,_DBuff);
        this ->_Sur_Name = char(0);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_PatroNymic,_DBuff);
        this ->_PatroNymic = char(0);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_Cell_Phone,_DBuff);
        this ->_Cell_Phone = char(0);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_Home_Phone,_DBuff);
        this ->_Home_Phone = char(0);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_E_mail,_DBuff);
        this ->_E_mail = char(0);
 
        fgets(_DBuff,1000,fp);
        strcpy(this ->_Home_Address,_DBuff);
        this ->_Home_Address = char(0);
    }
    else
    {
        cout << "Error opening file for reading." << endl;
    }
    fclose (fp);
    fp = 0;
}
 
ostream & operator << (ostream &stream, PhoneBook obj)
{
    stream << obj._Name << endl;
    stream << obj._Sur_Name << endl;
    stream << obj._PatroNymic << endl;
    stream << obj._Cell_Phone << endl;
    stream << obj._Home_Phone << endl;
    stream << obj._E_mail << endl;
    stream << obj._Home_Address << endl;
    return stream;
}
void PhoneBook::_Menu_of_PhoneBook(PhoneBook *obj, FILE *fp, char *_DBuff, char *_TempBuff, char *_TStr, int choise)
{
    cout << "\tMENU:" << endl;
    cout << "1. Add data to the database:" << endl;
    cout << "2. Delete data from the database:" << endl;
    cout << "3. Display the data in the database:" << endl;
    cout << "4. Exit:" << endl << endl;
    cout << "Please make your choice:" << endl;
    cin >> choise;
    switch (choise)
    {
    case 1:
        obj ->_Add_Data(obj,fp,_TempBuff,_TStr);
        break;
    case 2:
        obj ->_Delete_Data(obj,fp,_DBuff);
        break;
    case 3:
        obj ->_Display_Data(obj,fp,_DBuff);
        cout << obj;
        break;
    default: 
        cout << "Selected the wrong menu item." << endl;  
    }
    system("pause > nul");
}