unit Unit10;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  Tproc = class(TForm)
    ListBox1: TListBox;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  proc: Tproc;

implementation

uses Unit1;

{$R *.dfm}

procedure Tproc.FormClose(Sender: TObject; var Action: TCloseAction);
begin
listbox1.Clear;
end;

end.