public IHttpActionResult PostComment(Comment comment)
        {
            string UserId = (from r in db.Users where r.UserName == comment.CreatedBy select r.Id).FirstOrDefault();
            comment.CreatedDate = DateTime.Now;
            comment.ModifiedDate = DateTime.Now;
            comment.ModifiedBy = comment.CreatedBy;
            comment.UserId = UserId;

            db.Comments.Add(comment);
            db.SaveChanges();

            return CreatedAtRoute("DefaultApi", new { id = comment.Id }, comment);
        }
        public IHttpActionResult PutComment(int id, Comment comment)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != comment.Id)
            {
                return BadRequest();
            }

            db.Entry(comment).State = EntityState.Modified;

            try
            {
                db.SaveChanges();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!CommentExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }