public EditClipModel()
        {
            clip = new Clip();

            AllCategories = new List<SelectListItem>();
            VideoCategories = new List<SelectListItem>();
            FotoCategories = new List<SelectListItem>();
        }
        public void SaveClip(Clip clip)
        {
            if (clip.Id == 0)
            {
                contex.Clip.Add(clip);
            }
            else
            {
                Clip dbEntry = contex.Clip.Find(clip.Id);
                if (dbEntry != null)
                {
                    dbEntry.Title = clip.Title;
                    dbEntry.Description = clip.Description;
                    dbEntry.Categories = dbEntry.Categories.Union(clip.Categories).ToList();
                    dbEntry.ImageData = clip.ImageData;
                    dbEntry.ImageMimeType = clip.ImageMimeType;
                }
                contex.Entry(dbEntry).State = System.Data.Entity.EntityState.Modified;
            }

            contex.SaveChanges();
        }