Doubly Linked List

[Vandalism]

Why does it breaks?
Unhandled exception at 0x001D8D52 in Project13.exe: 0xC0000005: Access violation writing location 0x00000008.

at line 32 head->prev = newNode;

 #include<iostream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;

struct Node
{
	int data;
	struct Node* next;
	struct Node* prev;
};

struct Node* head;

struct Node* GetNewNode(int x)
{
	Node* newNode = new Node();
	newNode->data = x;
	newNode->prev = NULL;
	newNode->next = NULL;
	return newNode;
}

void InsertAtHead(int x)
{
	struct Node* newNode = GetNewNode(x);
	if (head = NULL)
	{
		head = newNode;
		return;
	}
	head->prev = newNode;
	newNode->next = head;
	head=newNode;
}

void Print()
{
	struct Node* temp = head;
	cout << "Forward: ";
	while (temp != NULL)
	{
		cout << temp->data << " ";
		temp = temp->next;
	}
	cout << endl;
}

void ReversePrint()
{
	struct Node* temp = head;
	if (temp == NULL) return;
	while (temp->next != NULL)
	{
		temp = temp->next;
	}
	cout << "Reverse: ";
	while (temp != NULL)
	{
		cout << temp->data << " ";
		temp = temp->prev;
	}
	cout << endl;
}

int main()
{
	head = NULL;
	InsertAtHead(2); Print(); ReversePrint();
	InsertAtHead(4); Print(); ReversePrint();
	InsertAtHead(6); Print(); ReversePrint();

	system("pause>0");
	return 0;
}

[Gamer2015]

Where does it break?

The problem looks like it is similar to this one:
http://www.cplusplus.com/forum/beginner/161549/

[Vandalism]

at line 32 head->prev = newNode;

[tscott8706]

I'm almost certain line 27 needs to be == rather than just one =.

On line 27 with just 1 equals sign, you assign head to NULL. Then the if condition evaluates NULL, which will be false. Then line 32 tries to access a member variable of a NULL pointer.

[Vandalism]

lmao yeah that's my only error. Thank you!