我链表为什么乱七八遭？？？

Question

我声明的链表如下：
type
   PImageInfor=^TImageInfor;
   TImageInfor=record
      filename:string;
      fileid:integer;
      next:PImageInfor;
      Prior:PImageInfor;
   end;然后定义了几个全局变量：
head,last,p:PImageInfor;在Form.Create事件中初始化全局变量：
         new(head);
         head.next:=nil;
         head.prior:=nil;
         last:=head;在button1中建立链表，在button2中遍历链表
button1的事件如下：
     for i:=0 to 10 do
     begin
            new(p);
            p.fileid:=i;
            p.next:=nil;
            p.Prior:=last;
            last.next:=p;
            last:=last.next;
            dispose(p);
    end;在button2中遍历：
     p:=head.next;
     while(p<>nil)do
     begin
        listbox1.items.add(inttostr(p.fileid));
        p:=p.next;
     end;按道理，在listbox中显示的应该是0~10这几个数。但是我得到的结果是6~10这几个数。
而且如果我在button2的遍历事件中，在p:=head.next后加一句：showmessage(inttostr(p.fileid)),在listbox中得到的数就只有一个0了。我已经要晕死了，乱七八糟的链表    

Answer 1

for i:=0 to 10 do
     begin
            new(p);
            p.fileid:=i;
            p.next:=nil;
            p.Prior:=last;
            last.next:=p;
            last:=last.next;
            dispose(p);
    end;好像有问题，不应该dispose(p)的，你试试。

Answer 2

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, Buttons;type
  PImageInfor=^TImageInfor;
   TImageInfor=record
      filename:string;
      fileid:integer;
      next:PImageInfor;
      Prior:PImageInfor;
   end;
  TForm1 = class(TForm)
    Button1: TButton;
    Shape1: TShape;
    BitBtn1: TBitBtn;
    ListBox1: TListBox;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
    head,last:PImageInfor;  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
var i: integer;
    p: PImageInfor;
begin
for i:=0 to 10 do
     begin
            new(p);
            p.fileid:=i;
            p.next:=nil;
            p.Prior:=last;
            last.next:=p;
            last:=last.next;
    end;end;procedure TForm1.FormCreate(Sender: TObject);
begin
         new(head);
         head.next:=nil;
         head.prior:=nil;
         last:=head;end;procedure TForm1.BitBtn1Click(Sender: TObject);
var p: PImageInfor;
begin
     p:=head.next;
     while(p <> nil)do
     begin
        listbox1.items.add(inttostr(p.fileid));
        p:=p.next;
     end;end;end.========================================================================
如果可以请支持一下
http://expert.csdn.net/Expert/topic/2308/2308724.xml?temp=.2405664