bool flag;
            int val;
            string output;
            double value1;
            double result;


            flag = double.TryParse(txtValue1.Text, out value1);
            if (flag == false)
            {
                MessageBox.Show("Only Integer type!");
                txtValue1.Clear();
                txtValue1.Focus();
                return;
            }

            result = value1 % 4;
            txtResult.Text = result.ToString();