domainup down menu validation
<p>I'm programming in C# Express 2010, and I have a form with a <code>DomainUpdown</code> menu that relates to a SQL database in the program meaning that the domainupdown's values are part of the database attribute, and I want to make validation in case the user forget to choose a value from domainupdown menu, a message will be shown with the question number, but this method isn't working once I run the program:</p>

<pre><code> public bool Check_Domain(DomainUpDown Choice, int num)
          {
              bool Check = false;
              if (Choice.SelectedItem == null)
              {
                  MessageBox.Show("You forgot to answer Question " + num + " !");
                  Check = true;
              }
              return Check;
          }
</code></pre>

<p>This is where the method is called:</p>

<pre><code>private void button2_Click(object sender, EventArgs e)
{
  Form9 f9 = null;
  bool Domain7;
  double FromParentForm= ParentForm();
  bool Domain7 = object5.Check_Domain(domainUpDown3, 8);
  if (Domain7 == false)
  {
    SendAge = int.Parse(textBox1.Text);
    Form8 f = new Form8(FromParentForm, SendAge, f9);
    f.Show();
    this.Hide();
  }
}
</code></pre>
