protected bool IsLinked(ImageSlide slide)
 {
     return !string.IsNullOrEmpty(slide.ImageLinkUrl);
 }
 protected string CaptionOrDefault(ImageSlide slide)
 {
     return IsHtmlCaption(slide.ImageTooltip) ?
         string.Concat("#", slide.SlideId.ToString()) :
         slide.ImageTooltip;
 }