Texboxbased filter checkboxlist and retain the value

Sorry here we go.....

Form1.cs

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


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

        private void Form1_Load(object sender, EventArgs e)
        {
            test();
            textBox1.TextChanged += new EventHandler(textBox1_TextChanged);
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            string filtertxt = textBox1.Text.Trim() as string;
            if (string.IsNullOrEmpty(filtertxt))
            {
                test();
            }
            else
            {
                checkedListBox1.Items.Clear();
                test1(filtertxt);
            }
        }

        public void test()
        {
            SqlConnection con = new SqlConnection("Persist Security Info=True;Initial Catalog=xxxx;Integrated Security=SSPI;Connect Timeout=5;Data Source=dbxxxxx");
            DataTable dt = new DataTable();
            SqlDataAdapter sda = new SqlDataAdapter("SELECT distinct column_name FROM information_schema.columns  where table_name IN ('tablename1', 'tablename2')", con);
            sda.Fill(dt);

            foreach (DataRow dr in dt.Rows)
            {
                //bool Check = Convert.ToBoolean(dr["IsSold"]);
                checkedListBox1.Items.Add(dr["column_name"].ToString());
            }       
        }

        public void test1(string txt)
        {
            SqlConnection con = new SqlConnection("Persist Security Info=True;Initial Catalog=xxxx;Integrated Security=SSPI;Connect Timeout=5;Data Source=dbxxxxx");
            DataTable dt = new DataTable();
            SqlDataAdapter sda = new SqlDataAdapter("SELECT distinct column_name FROM information_schema.columns  where table_name IN ('tablename1', 'tablename2') and column_name like '%" + txt + "%' ", con);
            sda.Fill(dt);

            foreach (DataRow dr in dt.Rows)
            {
                //bool Check = Convert.ToBoolean(dr["IsSold"]);
                checkedListBox1.Items.Add(dr["column_name"].ToString());
            }
        }

        private void checkedListBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            List YrStrList = new List();

            for (int i = 0; i < checkedListBox1.Items.Count; i++)
            {
                if (checkedListBox1.GetItemChecked(i))
                {
                    // If the item is selected, add the value to the list.
                    YrStrList.Add(checkedListBox1.Items[i].ToString());
                }
                else
                {
                    // Item is not selected, do something else.
                }
            }
            // Join the string together using the ; delimiter.
            String YrStr = String.Join(";", YrStrList.ToArray());
            MessageBox.Show(YrStr);
            // Write to the page the value.

            //myString = "101,102,103,104,105,106,107,108,109";

            foreach (string value in YrStr.Split(';'))
            {
             //   checkedListBox2.Items.Add(value);
            }

           
        }

    }
}


Designer File.....


namespace CheckedList
{
    partial class Form1
    {
        ///

        /// Required designer variable.
        ///

        private System.ComponentModel.IContainer components = null;

        ///

        /// Clean up any resources being used.
        ///

        /// true if managed resources should be disposed; otherwise, false.
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        ///

        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        ///

        private void InitializeComponent()
        {
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.checkedListBox1 = new System.Windows.Forms.CheckedListBox();
            this.SuspendLayout();
            //
            // textBox1
            //
            this.textBox1.Location = new System.Drawing.Point(106, 35);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(175, 20);
            this.textBox1.TabIndex = 0;
            this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
            //
            // checkedListBox1
            //
            this.checkedListBox1.CheckOnClick = true;
            this.checkedListBox1.FormattingEnabled = true;
            this.checkedListBox1.Location = new System.Drawing.Point(106, 62);
            this.checkedListBox1.Name = "checkedListBox1";
            this.checkedListBox1.ScrollAlwaysVisible = true;
            this.checkedListBox1.Size = new System.Drawing.Size(175, 184);
            this.checkedListBox1.TabIndex = 1;
            this.checkedListBox1.SelectedIndexChanged += new System.EventHandler(this.checkedListBox1_SelectedIndexChanged);
            //
            // Form1
            //
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(587, 275);
            this.Controls.Add(this.checkedListBox1);
            this.Controls.Add(this.textBox1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.CheckedListBox checkedListBox1;
    }
}