[Setup]
AppName=My Program
AppVersion=1.5
DisableWelcomePage=yes
DefaultDirName={pf}\My Program

[Code]
var
  // variables that will hold references of your custom pages
  MyPage1: TWizardPage;
  MyPage2: TWizardPage;

procedure InitializeWizard;
begin
  // resize and move the next button
  WizardForm.NextButton.Left := WizardForm.NextButton.Left - 50;
  WizardForm.NextButton.Width := WizardForm.NextButton.Width + 50;
  // store the reference of the first page
  MyPage1 := CreateCustomPage(wpSelectDir, 'Page 1 Caption', 'Page 1 Description');
  // store the reference of the second page
  MyPage2 := CreateCustomPage(MyPage1.ID, 'Page 2 Caption', 'Page 2 Description');
end;

procedure CurPageChanged(CurPageID: Integer);
begin
  case CurPageID of
    MyPage1.ID:
    begin
      // this code executes for the first page, so let's setup the buttons however you want
      WizardForm.BackButton.Visible := False;
      WizardForm.NextButton.Caption := '&Next';
      WizardForm.CancelButton.Caption := '&Abort';
    end;
    MyPage2.ID:
    begin
      // this code executes for the second page, so let's setup the buttons however you want
      WizardForm.BackButton.Visible := False;
      WizardForm.NextButton.Caption := '&Agree and Install';
      WizardForm.CancelButton.Caption := '&Decline';
    end;
  end;
end;