linked lists

[murva]

Hello,

I am hving a hard time trying to figure out how to build linked lists:Please see below the code I wrote:

#include <iostream>

using namespace std;


class Node
{public:

int value;
Node *post;
Node *prev;

Node(int a){value=a;post=NULL;prev=NULL;}
Node(){};

};

class nodeList
{

public:
	Node *head;
	

	nodeList()
	{
		head=new Node;
		head=NULL;
		


	};
	~nodeList(){};

	void add(Node obj)
	{
		if(head==NULL)
		{

		Node *tmp=new Node;
		tmp=&obj;
		head=tmp;
		obj.prev=NULL;
		obj.post=NULL;
		
		}
		else
		{
			Node *tmp=new Node;
			tmp=&obj;
			obj.post=head;
			head->prev=&obj;
			obj.prev=NULL;
			head=tmp;
		
			

		}
		
	
	}

	void print()
	{ 
		cout<<head->value;

	}

};


int main()
{

	Node a(10);
	Node c(22);

	nodeList b;
	b.add(a);
	b.add(c);

	b.print();
	

}

Why the method print shows me strange values? It does not hold the information that I set for it before? Any suggestion to improve code?

Thanks