c# & SQL newbie

Hi I am learning to code in C#. But I am stuck at one place. I am trying to connect to SQL server through C#

I am using VS 2005 and below is the code.

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace WindowsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        System.Data.SqlClient.SqlConnection con;
        DataSet ds1;
        System.Data.SqlClient.SqlDataAdapter da;
        DataRow dRow;

        private void Form1_Load(object sender, EventArgs e)
        {
            con = new System.Data.SqlClient.SqlConnection();
            ds1 = new DataSet();
            con.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=C:\\TransNo.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";
            
            con.Open();
            
            string sql = "SELECT * From tblTransNo";
            da = new System.Data.SqlClient.SqlDataAdapter(sql, con);

            da.Fill(ds1, "TransNo");
            NavigateRecords();
            con.Close();
        }

        private void NavigateRecords()
        {
            DataRow dRow = dsl.Tables["TransNo"].Rows[0];

            textBox1.Text = dRow.ItemArray.GetValue(2).ToString();
        }
    }
} 

Here are the errors I am getting

Error 1 The name 'dsl' does not exist in the current context C:\Documents and Settings\User\My Documents\Visual Studio 2005\Projects\WindowsApplication2\WindowsApplication2\Form1.cs 40 28 WindowsApplication2
Any help is appreciated.