Provider Design Patterns in NET 2.0

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

namespace CompanyName.PhoneBook.PhoneBookApplication
{
    public partial class Main : Form
    {
        public Main()
        {
            InitializeComponent();
        }

        private void Main_Load(object sender, EventArgs e)
        {
            try
            {
                if (ConfigurationManager.ConnectionStrings["strcon"] != null)
                {
                    txtStrcon.Text = ConfigurationManager.ConnectionStrings["strcon"].ToString();
                }
            }
            catch (Exception ex) { MessageBox.Show(ex.ToString()); }//"Can't find connection string in app.config"); }
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            if (config.AppSettings.Settings["strcon"] != null)
                config.AppSettings.Settings["strcon"].Value = txtStrcon.Text.Trim();
            else
                config.AppSettings.Settings.Add("strcon", txtStrcon.Text.Trim());
            MessageBox.Show("Saved successfully", "Successfully");
        }

        private void btnAddPerson_Click(object sender, EventArgs e)
        {
            AddPerson frmAddperson = new AddPerson(true,0);
            frmAddperson.ShowDialog();
        }

        private void btnSerch_Click(object sender, EventArgs e)
        {
            AdvancedSearch frmSearch = new AdvancedSearch();
            frmSearch.ShowDialog();
        }

        private void btnManageGroups_Click(object sender, EventArgs e)
        {
            ManageGroups frmManage = new ManageGroups();
            frmManage.ShowDialog();
        }
    }
}