Subtract Two Numbers in Delphi

unit subtract;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Label3: TLabel;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
   private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  Number1, Number2, Result: Double;
begin
        // Convert input strings to numbers
  Number1 := StrToFloat(Edit1.Text);
  Number2 := StrToFloat(Edit2.Text);

  // Perform subtraction
  Result := Number1 - Number2;

  // Display result
  Label3.Caption := 'The difference between ' + FloatToStr(Number1)
  + ' and '+ FloatToStr(Number2) + ' is  '   + FloatToStr(Result) + '.';
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
edit1.Text := '';
edit2.Text := '';
label3.Caption := '';
edit1.SetFocus;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
if MessageDlg('Are you sure you want to close this program', mtConfirmation,
    [mbYes, mbNo], 0) = mrYes then
  begin
    Close;  // This will unload/close the form
  end
  else
   begin
     edit1.Text := '';
     edit2.Text := '';
     label3.Caption := '';
     edit1.SetFocus;
   end;
end;


procedure TForm1.Button4Click(Sender: TObject);
begin

  // Show message box with custom icon
  Application.MessageBox(
    'Created By Dr. Jake Rodriguez Pomperada,PHD-TM',
    'About this program',
    MB_OK + MB_ICONINFORMATION
  );
end;

end.