Problem with lists, eliminating duplicates

[Vik70r]

Hello guys! I need a bit of an advice with lists. Basically, i generated a list and created a function that should delete any duplicate information.

  #include <iostream>
using namespace std;

typedef struct nod{
	int info;
	nod *next;
}NOD, *PNOD;

PNOD add(PNOD head, int info_new)
{
	if (head == NULL)
	{
		PNOD p = new NOD;
		if (!p)
		{
			cout << "Memory was not allocated" << endl;
			return NULL;
		}
		p->info = info_new;
		p->next = NULL;
		return p;
	}

	PNOD p = head;
	while (p->next != NULL)
		p = p->next;

	PNOD e = new NOD;
	e->info = info_new;
	e->next = NULL;
	p->next = e;
	return head;
}

PNOD create(int n, int *v)
{
	PNOD p = NULL;
	for (int i = 0; i < n; i++)
		p = add(p, v[i]);
	return p;
}

void print(PNOD head)
{
	PNOD p = head;
	while (p)
	{
		cout << p->info << "  ";
		p = p->next;
	}
	cout << endl;
}


PNOD del_nod(PNOD head, int info_old)
{
	PNOD p = head;
	while (p->next->info != info_old)
		p = p->next;

	PNOD s = p->next;
	p->next = s->next;
	delete s;
	return head;
}

void del_duplicates(PNOD head)
{
	PNOD p = head;
	while (p)
	{
		PNOD x = p;
		while (x->next->next!=NULL)
		{
			x = x->next;
			if (p->info == x->info) del_nod(p, x->info);
		}
		p = p->next;
	}
}


int main()
{
	PNOD head = NULL;
	int dim;
	int *v;
	cout << "List size : "; cin >> dim;
	cout << endl;
	v = new int[dim];
	
	for (int i = 0; i < dim; i++)
	{
		cout << "v[" << i << "]= ";
		cin >> v[i];
	}
	
	head = create(dim, v);
	print(head);
	del_duplicates(head);
	print(head);
	system("PAUSE");
	return 0;
}

Problem is, i get an unhandled exception when i hit the del_duplicates function, and i'm not quite sure why that is. Any suggestions?