Show/hide sitemap if user is logged in

protected void btnLog_Click(object sender, EventArgs e)

{

    SqlConnection conn1 = new SqlConnection("Data Source=GATE-PC\\SQLEXPRESS;Initial Catalog=dbUsers;Integrated Security=True");

    conn1.Open();

    SqlCommand cmdd = new SqlCommand("select * from Users where UserName = @user AND Password = @pass", conn1);

    SqlParameter param = new SqlParameter();

    SqlParameter param1 = new SqlParameter();

    param.ParameterName = "@user";

    param1.ParameterName = "@pass";

    param.Value = txtuser.Text;

    param1.Value = txtpass.Text;

    cmdd.Parameters.Add(param);

    cmdd.Parameters.Add(param1);

    SqlDataReader reader = cmdd.ExecuteReader();

    if (reader.HasRows)

    {

        reader.Read();

        MessageBox("Login Successful");

        clear();

    }

    else

    {

        MessageBox("Invalid Username/Password");

    }

}

           
what i want to achieve is when a user is not logged in Menu1 will display and NavigationMenu will hide but if a user is logged in Menu1 will hide then NavigationMenu will show. Kindly help me with this. I'm using asp.net with c#. Thanks and God Bless