private void AES_button_Click(object sender, EventArgs e)
 {
     AES aes = new AES();
      AESPTextBox.Text = aes.decrypt(tb_clientmsg.Text, KeyTextBox.Text);
 }
        private void AES_button_Click(object sender, EventArgs e)
        {
            AES aes = new AES();

            AESPTextBox.Text = aes.decrypt(tb_clientmsg.Text, KeyTextBox.Text);
        }