linked lists question

[smallmos]

i'm having trouble inserting/printing data from my linked list, i'm not sure if the data is going into the list or there is a problem with my print function...any ideas?

#ifndef ListOfDoubles_H
#define ListOfDoubles_H

class ListOfDoubles
{
private:
	struct node
	{
		double data;
		node *next;//pointer to next node
	}
	*head;//first node in list
public:
	ListOfDoubles();
	void insert(double number);
	void display();
	double deleteMostRecent();
	int count();
	//~ListOfDoubles();
};
#endif; 

#include "ListOfDoubles.h"
#include<iostream>
using namespace std;

ListOfDoubles::ListOfDoubles()
{
	head = NULL;
}

void ListOfDoubles::insert(double num)
{
	node *tempNode, *newNode;
	if(head == NULL)//if there's no nodes
	{
		newNode = new node;
		newNode->data = num;
		newNode->next = NULL;
	}
	else
	{
		tempNode = head;
		while(tempNode->next != NULL)
		{
			tempNode = tempNode->next;
		}
		newNode = new node;
		newNode->data = num;
		newNode->next = NULL;
		tempNode->next = newNode;
	}
}

void ListOfDoubles::display()
{
	node *tempNode = head;
	while(tempNode != NULL)
	{
		cout << tempNode->data;
		tempNode = tempNode->next;
	}
	
	/* a differant print function i tried
	node *tempNode;
	for(tempNode = head; tempNode != NULL; tempNode = tempNode->next)
		{
			cout << tempNode->data << endl;
		}
		*/
}

#include "ListOfDoubles.h"
#include<iostream>
using namespace std;

int main()
{
	ListOfDoubles list;

	list.insert(3);
	list.insert(4);
	list.insert(5);
	list.insert(6);

	list.display();

	system("pause");
	return 0;
}

[ne555]

You never update 'head'

[smallmos]

thanks.