protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            if (!String.IsNullOrEmpty(Request.QueryString["id"]))
            {
                string guid = Request.QueryString["id"].ToString();
                using (var db = new Entities())
                {
                    var q = from u in db.Users
                            where u.UniGuid == guid
                            select u;
                    if (q.Any())
                    {
                        Label1.Text = "You have to fill the blank below to change your password";

                    }
                    btnReset.Visible = true;
                    txtPassword.Visible = true;
                }
            }

        }
    }
    protected void btnReset_Click(object sender, EventArgs e)
    {

        string guid = Request.QueryString["id"].ToString();
        using (var db = new Entities())
        {
            var q = from u in db.Users
                    where u.UniGuid == guid
                    select u;
            if (q.Any())
            {
                //Users u = new Users();
                //u.Password = txtPassword.Text;
                q.First().Password = txtPassword.Text;
                db.SaveChanges();
            }
        }

    }

var objUser = db.Users
            .FirstOrDefault(x => x.UniGuid.Equals(guid));