C# Datset with Sql Server Data Provider

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connetionString = null;
            SqlConnection connection ;
            SqlCommand command ;
            SqlDataAdapter adapter = new SqlDataAdapter();
            DataSet ds = new DataSet();
            int i = 0;
            string sql = null;

            connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password";
            sql = "Your SQL Statement Here";

            connection = new SqlConnection(connetionString);

            try
            {
                connection.Open();
                command = new SqlCommand(sql, connection);
                adapter.SelectCommand = command;
                adapter.Fill(ds);
                adapter.Dispose();
                command.Dispose();
                connection.Close();

                for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
                {
                    MessageBox.Show(ds.Tables[0].Rows[i].ItemArray[0] + " -- " + ds.Tables[0].Rows[i].ItemArray[1]);

                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }
        }
    }
}