unit LuaStack; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, Main, ExtCtrls, JvComponent, JvDockControlForm; type TfrmLuaStack = class(TForm) lstLuaStack: TListBox; JvDockClient1: TJvDockClient; procedure FormActivate(Sender: TObject); private { Private declarations } public { Public declarations } end; var frmLuaStack: TfrmLuaStack; implementation {$R *.dfm} procedure TfrmLuaStack.FormActivate(Sender: TObject); begin SendMessage(lstLuaStack.Handle, LB_SetHorizontalExtent, 1000, longint(0)); end; end.