public void UpdateUserDescription(string id, string description)
 {
     var old = FindUserDescription(id);
     if (old == null)
     {
         userdescription item = new userdescription { Id_User = id, Description = description };
         context.userdescriptions.Add(item);
     }
     else
     {
         old.Description = description;
     }
     context.SaveChanges();
 }