如何修改文件属性？(100分)

请问，如何在程序中修改某个文件的属性，如只读，存档等？

procedure TFMForm.Properties1Click(Sender: TObject);
var
Attributes, NewAttributes: Word;
begin
with FileAttrForm do
begin
FileDirName.Caption := FileList.Items[FileList.ItemIndex];
{ set box caption }
PathName.Caption := FileList.Directory;
{ show directory name }
ChangeDate.Caption :=
DateTimeToStr(FileDateToDateTime(FileAge(FileList.FileName)));
Attributes := FileGetAttr(FileDirName.Caption);
{ read file attributes }
ReadOnly.Checked := (Attributes and faReadOnly) = faReadOnly;
Archive.Checked := (Attributes and faArchive) = faArchive;
System.Checked := (Attributes and faSysFile) = faSysFile;
Hidden.Checked := (Attributes and faHidden) = faHidden;
if ShowModal <> id_Cancel then { execute dialog box }
begin
NewAttributes := Attributes;
{ start with original attributes }
if ReadOnly.Checked then
NewAttributes := NewAttributes or faReadOnly
else
NewAttributes := NewAttributes andnot faReadOnly;
if Archive.Checked then
NewAttributes := NewAttributes or faArchive
else
NewAttributes := NewAttributes andnot faArchive;
if System.Checked then
NewAttributes := NewAttributes or faSysFile
else
NewAttributes := NewAttributes andnot faSysFile;
if Hidden.Checked then
NewAttributes := NewAttributes or faHidden
else
NewAttributes := NewAttributes andnot faHidden;
if NewAttributes <> Attributes then { if anything changed... }
FileSetAttr(FileDirName.Caption, NewAttributes);
{ ...write the new values }
end;
end;
end;

用FileSteAttr('Filename',33); 设为只读，33 改为32 去掉只读。可用FileGetAttr('filename');得到文件不同属性的值。

错了，是用FileSetAttr();