procedure TForm1.Button1Click(Sender: TObject);
var
   PathBuffer: array[0..255] of char;
   FilePart: PChar;
begin
  Label1.Caption := ExtractFileName(FileListBox1.FileName);
  GetFullPathName(PChar(Label1.Caption), 255, PathBuffer, FilePart);
  Label2.Caption := string(PathBuffer);
end;