Treeview menu Control by access user

guys. I wanna to get a specific value for sql server. The sql table is as below now.

ID / PW / Depart

AAA / 1234 / 1

BBB / 2345 / 2

...

LKL / 8765 / 9

For example, When LKL user access to Logon Form, I want to get the Depart code 9.

But it working not. Maybe some problem. But I couldn't find that no more. :(

Here is my code. I will ppriciate any ideas.

Thanks.

private void MForm_Load(object sender, EventArgs e)
        {
            Logon lf = new Logon();
            String tx = lf.IDTBox.Text;
            String str = "Server = 102.201.10.17; Database = Dorw; UID = sa; Password = 565p89";
            String qur = "SELECT Depart FROM dbo.PW WHERE Name = @tx";
            SqlConnection con = new SqlConnection(str);
            SqlCommand cmd = new SqlCommand(qur, con);
            cmd.Parameters.AddWithValue("@tx", tx);
            con.Open();
            using(SqlDataReader reader = cmd.ExecuteReader())
            switch (reader.ToString())
            {
            case "0":
                break;

            case "1":
                treeView1.Nodes[1].Nodes[1].Remove();
                break;

            case "9":
                treeView1.Nodes[0].Nodes[0].Remove();
                treeView1.Nodes[1].Nodes[0].Remove();
                treeView1.Nodes[1].Nodes[1].Remove();
                break;
            }
       con.Close();
       }