private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            localhost.Service1 ser    = new localhost.Service1();
            BindingSource      source = new BindingSource();

            ser.showSubjects(txtUserName.Text);
            source.DataSource            =
                dataGridView1.DataSource = source;
        }
        private void btnShowSubject_Click(object sender, EventArgs e)
        {
            localhost.Service1 ser = new localhost.Service1();
            bool isValidStudentResult;
            bool isValidStudentResultSpecified;

            ser.isValidStudent(txtUserName.Text, out isValidStudentResult, out isValidStudentResultSpecified);
            if (isValidStudentResult)
            {
                BindingSource source = new BindingSource();
                ser.showSubjects(txtUserName.Text);
                source.DataSource        = ser.showSubjects(txtUserName.Text);
                dataGridView1.DataSource = source;
            }
            else
            {
                MessageBox.Show("Invalid Student");
            }
        }