Help With Data Structures (Singly Linked Lists)

Question

Need help inserting user entered name alphabetically into SSL
import java.util.Scanner;
class SLLNode<T> {
    public T info;
    public SLLNode<T> next;
    public SLLNode() {
        next = null;
    public SLLNode(T el) {
        info = el; next = null;
    public SLLNode(T el, SLLNode<T> ptr) {
        info = el; next = ptr;
class SLL<T> {
    protected SLLNode<T> head, tail;
    public SLL() {
        head = tail = null;
    public boolean isEmpty() {
        return head == null;
    public void addToHead(T el) {
        head = new SLLNode<T>(el,head);
        if (tail == null)
            tail = head;
    public void addToTail(T el) {
        if (!isEmpty()) {
            tail.next = new SLLNode<T>(el);
            tail = tail.next;
        else head = tail = new SLLNode<T>(el);
    public T deleteFromHead() {
        if (isEmpty())
             return null;
        T el = head.info;
        if (head == tail)      
             head = tail = null;
        else head = head.next;
        return el;
    public T deleteFromTail() {
        if (isEmpty())
             return null;
        T el = tail.info;
        if (head == tail)     
             head = tail = null;
        else {                 
             SLLNode<T> tmp;   
             for (tmp = head; tmp.next != tail; tmp = tmp.next);
             tail = tmp;       
             tail.next = null;
        return el;
    public void delete(T el) { 
        if (!isEmpty())
            if (head == tail && el.equals(head.info))
                 head = tail = null;     
            else if (el.equals(head.info))
                 head = head.next;   
            else {                   
                 SLLNode<T> pred, tmp;
                 for (pred = head, tmp = head.next;
                      tmp != null && !tmp.info.equals(el);
                      pred = pred.next, tmp = tmp.next);
                 if (tmp != null) {  
                     pred.next = tmp.next;
                     if (tmp == tail)
                        tail = pred;
    public void printAll() {
        for (SLLNode<T> tmp = head; tmp != null; tmp = tmp.next)
            System.out.print(tmp.info + " ");
    public boolean isInList(T el) {
        SLLNode<T> tmp;
        for (tmp = head; tmp != null && !tmp.info.equals(el); tmp = tmp.next);
        return tmp != null;
class Passengers extends SLL<String>{
     Scanner kb = new Scanner (System.in);
     String name;
     Passengers(){
     void reserveTicket(){
          SLLNode<String> temp;
          System.out.println("Please enter your Last Name");
          name = kb.next();
          if(isEmpty())
               addToHead(name);
          else
               if(name.compareTo(head.info) <= 0)
                    addToHead(name);
               else
                    if(name.compareTo(head.info) > 0){
                         while(head.next == null){
                              temp = head.next;
                              name.compareTo(temp.info);
                                   if(name.compareTo(temp.info) <= 0)
                                        temp.info = name;
     void cancelReserve(){
          System.out.println("Please enter your Last Name");
          name = kb.next();
          if(isInList(name)){
               delete(name);
               System.out.println("Your reservation has safely been removed");
          else System.out.println("That reservation does not exist");
     void checkReserve(){
          System.out.println("Please enter your Last Name");
          name = kb.next();
          if(isInList(name)){
               System.out.println("You currently have a reservation for this flight");
               printAll();
          else System.out.println("Sorry, there is no reservation for this flight under that name");
     void showPassengers(){
          if(! isEmpty())
               printAll();
          else System.out.println("There are no passengers for this flight");
class Program2_19{
     public static void main(String[] a) {
          Passengers passList = new Passengers();
          Scanner kb = new Scanner (System.in);
          int choice;
          int option = 1;
          while(option == 1){
               System.out.println("Push 1 to Reserve a ticket");
               System.out.println("Push 2 to Cancel a reservation");
               System.out.println("Push 3 to Check reservations");
               System.out.println("Push 4 to Display all passengers");
               choice = kb.nextInt();
               System.out.println();
               if(choice == 1)
                    passList.reserveTicket();
               else if(choice == 2)
                    passList.cancelReserve();
               else if(choice == 3)
                    passList.checkReserve();
               else
                    passList.showPassengers();
          System.out.println("Would you like to perform another action?");
          System.out.println("Press 1 for yes, or 2 for no");
          option = kb.nextInt();
          System.out.println();
}

Answer 1

how do i step thru my list to find the correct spot to insert the name...I kno it has to be done with compareTo() but what do i compare the name with?..the node?.. the head? the tail?