private void button1_Click(object sender, EventArgs e)
        {
            textBox3.Text = textBox1.Text + "님~~!"+ Environment.NewLine+ "당신의 학번은 " + textBox2.Text + Environment.NewLine + " 입니다!!";
            MessageBox.Show(textBox3.Text,"[공지 사항]");
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Dispose();
        }