unit DimmerForm;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs;

type
  TfmDimmerForm = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    procedure Display;
  end;

var
  fmDimmerForm: TfmDimmerForm;

implementation

{$R *.dfm}

procedure TfmDimmerForm.Display;
begin
  with Self do
  begin
    Left := Application.MainForm.Left;
    Top := Application.MainForm.Top;
    Width := Application.MainForm.Width;
    Height := Application.MainForm.Height;
    Show;
  end;
end;

procedure TfmDimmerForm.FormCreate(Sender: TObject);
begin
  AlphaBlend := true;
  AlphaBlendValue := 128;
  BorderStyle := bsNone;
end;

end.