ปัญหาการตรวจสอบสิทธิ์ ASP.net ช่วยแก้หน่อยครับ ไม่เข้าใจเท่าไหร่ครับ

public partial class login2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    
        protected void btnlogin(object sender, EventArgs e)
        {
            String conn;
            conn = "Data Source=.\\SQLEXPRESS;Initial Catalog=CarReserveDb;Integrated Security=True";

            SqlConnection objsqlconn = new SqlConnection(conn);
            objsqlconn.Open();

            SqlCommand cmd = new SqlCommand("select * from Userdata where Username=@Username and Password=@Password  ", objsqlconn);
            cmd.Parameters.AddWithValue("@Username", TextBox1.Text);
            cmd.Parameters.AddWithValue("@Password", TextBox2.Text);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);

        if (dt.Rows.Count > 0)
        {
           
            if (dt.Rows[0]["status"]== "admin")
                 {
                    Session["Username"] = TextBox1.Text;
                    Response.Redirect("admin.aspx");
               
                }
                else
                {
                    Session["Username"] = TextBox1.Text;
                    Response.Redirect("user.aspx");
           
                }

            }
            else
            {
                Label1.Text = "* Invalid username or password. Please try again.";
            }

        }

   
}