protected void Page_Load(object sender, EventArgs e)
        {
            if (Session["userId"] == null)
            {
                //Response.Redirect("index.aspx");
            }
            else
            {
                var sessionUserId = Session["userId"].ToString();
                //EntityDataSource1.Where = "it.[user_id] = '" + sessionUserId + "'";

                studymsl_dbEntities db = new studymsl_dbEntities();
                GridView1.DataSource = db.progresses.Where(a => a.user_id.Contains(sessionUserId)).ToList();
                GridView1.DataBind();
            }
        }