function

unit Unit1;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;

type

  TForm1 = class(TForm)

    Button1: TButton;

    procedure Button1Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

function  sum(x,y:integer): Integer;

  var    m,n: Integer;

    begin

        result:=m+n;

    end;

procedure TForm1.Button1Click(Sender: TObject);

    var    a:Integer;

begin

    a:= sum(10,5);

    ShowMessage(IntToStr(a));

end;

end.