internal void AddExpandoAttribute(HtmlTextWriter writer, string controlId, string attributeName, string attributeValue, bool encode)
 {
     RequireEitherFieldValidator.AddExpandoAttribute((Control)this, writer, controlId, attributeName, attributeValue, encode);
 }
		/// <summary>Adds a required field validator.</summary>
		/// <param name="container">The container control for this validator.</param>
		/// <param name="editor">The editor control to validate.</param>
		protected override Control AddRequiredFieldValidator(Control container, Control editor)
		{
			SelectingUploadCompositeControl composite = editor as SelectingUploadCompositeControl;
			if (composite != null)
			{
				RequireEitherFieldValidator rfv = new RequireEitherFieldValidator();
				rfv.ID = Name + "_rfv";
				rfv.ControlToValidate = composite.SelectorControl.ID;
				rfv.OtherControlToValidate = composite.UploadControl.ID;
				rfv.Display = ValidatorDisplay.Dynamic;
				rfv.Text = GetLocalizedText("RequiredText") ?? RequiredText;
				rfv.ErrorMessage = GetLocalizedText("RequiredMessage") ?? RequiredMessage;
				editor.Controls.Add(rfv);

				return rfv;
			}
			return null;
		}