public IHttpActionResult Put(int?id, Mark mark)
{
if (!ModelState.IsValid)
{
return(BadRequest(ModelState));
}
if (id == null || id != mark.Id)
{
return(BadRequest());
}
if (!MarkExists((int)id))
{
return(NotFound());
}
_repo.MarkAsModified(mark);
_repo.SaveChanges();
return(Ok(mark));
}