private void txtNationId_Validated(object sender, EventArgs e)
{
if (Frm == "Add")
{
DataTable dt = new DataTable();
dt = std.VerifiedStdId(txtNationId.Text);
if (dt.Rows.Count > 0)
{
MessageBox.Show("هذا الطالب موجود مسبقاً", "تنبيه");
txtNationId.Focus();
txtNationId.SelectionStart = 0;
}
}
}