谁知道为什么，系统造成的吗

unit unit1;

interface

uses
  windows, messages, sysutils, variants, classes, graphics, controls, forms,
  dialogs, stdctrls, extctrls, filectrl;

type
  tform1 = class（tform)
    directorylistbox1: tdirectorylistbox;
    labelededit1: tlabelededit;
    button1: tbutton;
    listbox1: tlistbox;
    drivecombobox1: tdrivecombobox;
    button2: tbutton;
    procedure button1click（sender: tobject);
    procedure button2click（sender: tobject);
  private
    { private declarations }
  public
  procedure findfiles（apath:string;afile:string);
    { public declarations }
  end;

var
  form1: tform1;
   targetfiles:string;
implementation

{$r *.dfm}

procedure tform1.button1click（sender: tobject);
begin
screen.cursor:=crhourglass;
try
listbox1.clear;
targetfiles:=labelededit1.text;
findfiles（directorylistbox1.directory,targetfiles);
finally
screen.cursor:=crdefault;
end;
end;
procedure tform1.findfiles（apath,afile:string);
var
findresult:integer;
fsearchrec,dsearchrec:tsearchrec;
function isdirnotation（adirname:string):boolean;
begin
result:=（（adirname='.') or （adirname='..'));
end;
begin
if apath[length（apath)]<>'\' then
apath:=apath+'\';
findresult:=findfirst（apath+afile,faanyfile+fahidden+fasysfile+fareadonly,fsearchrec);
try
while findresult=0 do begin
listbox1.items.add（fsearchrec.name);
findresult:=findnext（fsearchrec);
end;
findresult:=findfirst（apath+'*.*',fadirectory,dsearchrec);
while findresult=0 do begin
if（（dsearchrec.attr and fadirectory)= fadirectory) and
not isdirnotation（dsearchrec.name) then
findfiles（apath+dsearchrec.name,targetfiles);
findresult:=findnext（dsearchrec);
end;
finally
findclose（fsearchrec);
end;

end;

procedure tform1.button2click（sender: tobject);
begin
listbox1.items.add（'aa');
end;
end.