title: server validate RadComboBox with Load on demand with Custom text is true
body: <p>How can I validate RadComboBox on the server side with LoadonDemand true and AllowCustomText is true? I have the following code but it doesn't validate correctly.</p>
  
  <pre><code>  protected void RadComboBox1ServerValidate(object sender, ServerValidateEventArgs arg)
      {
          arg.IsValid = RadComboBox1.SelectedValue.Length &gt; 0;
      }
  </code></pre>