Thread: Doubly linked list

In the following code, I've implemented a double linked list in which each node is a structure with the following fields:
firstName, seciondName, CNP, Email;
When I call the function ptr->DeleteNODE for the fifth time to delete the last node left in the list the code is no longer running.
Deleting nodes is done from the beginning of the list.
I do not understand why ?
Can you help me ?

Code:

#include <iostream>
#include <cstring>
using namespace std;


struct Persons
{
    string firstName;
    string secondName;
    string CNP;
    string Email;
};


class NODE
{
private:
    NODE *next;
    NODE *previous;
public:
    Persons *box = new Persons();
    NODE(string firstName, string secondName, string CNP, string Email)
    {
        box->firstName = firstName;
        box->secondName = secondName;
        box->CNP = CNP;
        box->Email = Email;
    }
    void SetNext(NODE *next)
    {
        this->next = next;
    }
    NODE* GetNext()
    {
        return next;
    }
    void SetPrevious(NODE *previous)
    {
        this->previous = previous;
    }
    NODE *GetPrevious()
    {
        return previous;
    }
};


class DoublyLinkedList
{
private:
    NODE *head;
public:
    DoublyLinkedList()
    {
        head = NULL;
    }
    bool isEmpty()
    {
        return head == NULL;
    }
    void AddNODE(NODE *newNode)
    {
        if (isEmpty())
        {
            newNode->SetPrevious(NULL);
            head = newNode;
        }
        else
        {
            NODE *temp = head;
            while (temp->GetNext() != NULL)
                temp = temp->GetNext();
            temp->SetNext(newNode);
            newNode->SetPrevious(temp);
        }
        newNode->SetNext(NULL);
    }
    void DeleteNODE()
    {
        if (isEmpty())
            cout << "\n List is Empty." << endl;
        NODE *temp = head;
        if (head->GetNext() != NULL)
        {
            head = head->GetNext();
            head->SetPrevious(NULL);
        }
        else
            head = NULL;
        delete temp;
    }
    void Print()
    {
        NODE *temp = head;
        while (temp != NULL)
        {
            cout << "\n First Name  : " << temp->box->firstName;
            cout << "\n Second Name : " << temp->box->secondName;
            cout << "\n CNP         : " << temp->box->CNP;
            cout << "\n Email       : " << temp->box->Email;
            temp = temp->GetNext();
            cout << endl;
        }
    }
};


int main()
{
    DoublyLinkedList *ptr = new DoublyLinkedList();


    NODE obj1("Dragu", "Stelian", "1911226284570", "[email protected]");
    NODE obj2("Dragu", "Mircea", "1891226284462", "[email protected]");
    NODE obj3("David", "Adrian", "1971226284462", "[email protected]");
    NODE obj4("Afrem", "Dragos", "1981246627446", "[email protected]");
    NODE obj5("Sandu", "Marius", "1984225774462", "[email protected]");


    ptr->AddNODE(&obj1);
    ptr->AddNODE(&obj2);
    ptr->AddNODE(&obj3);
    ptr->AddNODE(&obj4);
    ptr->AddNODE(&obj5);


    ptr->Print();


    ptr->DeleteNODE();
    ptr->DeleteNODE();
    ptr->DeleteNODE();
    ptr->DeleteNODE();
    ptr->DeleteNODE();




    ptr->Print();
    return 0;
}