for (int i = 2; i <= 100; i++)

        {

            bool s = false;

            for (int j = 2; j <= i / 2 + 1; j++)

            {

                if (i % j == 0)

                {

                     s = true;

                     break;

                }


            }

            if (!s)

            {


                this.Label1.Text += i.ToString() + ",</br>";

            }

        }