I can't seem to figure out how to do this. The code I have in there (RemoveAll function) keeps leading to many program crashes. Please help.

Friends.h
Code:
class linkedlist {

public:

	char name[100];
	int birthday;
	int phone;
	linkedlist* nextstudent;

linkedlist ();
void Insert();
void RemoveAll();
//void Reset();
//int* GetNext();
~linkedlist ();

};
Friends.cpp
Code:
#include <iostream>
#include "friends.h"
using namespace std;

int choice = 0;
int counter = 0;

linkedlist* student;
linkedlist* headstudent;
linkedlist* prevstudent = NULL;

linkedlist functions;

linkedlist::linkedlist () {

strncpy_s(name, "No Input", 9);
birthday = 0;
phone = 0; }

void linkedlist::Insert ()
{
	student = new linkedlist;
	if (prevstudent == NULL){
		headstudent = student; }
	else {
		prevstudent->nextstudent = student; }

	cout<<"\nEnter the friend's name: ";
	cin>>student->name;
	cout<<"Enter the friend's birthday: (MMDD) ";
	cin>>student->birthday;
	cout<<"Enter the friend's phone number: (No Dashes) ";
	cin>>student->phone;

	cout<<"\n\n";

	prevstudent = student;
	prevstudent->nextstudent = NULL;
	student = headstudent;

}

void linkedlist::RemoveAll () {

	student = headstudent;

	do {
		prevstudent = student;
		student = student->nextstudent;
    	delete prevstudent;
	} while (student != NULL);

}

linkedlist::~linkedlist () {

	RemoveAll(); }

int Print()
{
	cout<<"\n\n";

	if (counter == 0) {
	cout<<functions.name<<"\nBirthday: "<<functions.birthday<<"\nPhone #: "<<functions.phone<<"\n\n"; }

	else {

	do {

		cout<<student->name<<"\nBirthday: "<<student->birthday<<"\nPhone: "<<student->phone<<"\n\n";
		student = student ->nextstudent;;
	} while (student != NULL);

	student = headstudent; }



//	for (int n = 0;n < total;n++) {  
//		cout<<"Name: "<<student->name<<"\nBirthday: "<<student->birthday<<"\nPhone #: "<<student->phone<<"\n\n"; }

	return 0;
}
int main ()
{

	while (choice != 4) {

	cout<<"Please select an option...\n\n1. Enter Data\n2. Print Data\n3. Erase All Data\n4. Quit\n\n";
	cin>>choice;

	if (choice == 1){
		functions.Insert(); }
	if (choice == 2) {
		Print(); }
	if (choice == 3) {
		functions.RemoveAll(); }

	}


	cout<<"\n";
	system("PAUSE");
	return 0;

}