unit NewFolderUnit; interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls; type TNewFolderForm = class(TForm) Label1: TLabel; InputBox: TEdit; Bevel1: TBevel; ButtonOK: TButton; ButtonCancel: TButton; procedure InputBoxChange(Sender: TObject); private public end; var NewFolderForm: TNewFolderForm; implementation {$R *.DFM} procedure TNewFolderForm.InputBoxChange(Sender: TObject); begin ButtonOK.Enabled := InputBox.Text <> ''; end; end.