Autocomplete combobox match any part of string not only beginning in VB.NET

using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace CB_Contains
{
    public partial class Form1 : Form
    {
        private Dictionary<String, System.Int32> CBFullList;
        private Dictionary<String, System.Int32> CBFilteredList;

        bool ComboBoxBusy;

        public Form1()
        {
            InitializeComponent();

            ComboBoxBusy = false;
            CBFullList = new Dictionary<string, Int32>();
            CBFilteredList = new Dictionary<string, Int32>();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            CBFullList.Add("None", 0);
            CBFullList.Add("abc 123", 1);
            CBFullList.Add("pqr 234", 2);
            CBFullList.Add("123 abc", 3);
            CBFullList.Add("pqr 123", 4);

            FilterList(false);
        }

        private void FilterList(bool show)
        {
            if (ComboBoxBusy == false)
            {
                String orgText;

                ComboBoxBusy = true;
                orgText = comboBox1.Text;

                comboBox1.DroppedDown = false;

                CBFilteredList.Clear();

                foreach (KeyValuePair<string, Int32> item in CBFullList)
                {
                    if (item.Key.ToUpper().Contains(orgText.ToUpper()))
                        CBFilteredList.Add(item.Key, item.Value);
                }

                if (CBFilteredList.Count < 1)
                    CBFilteredList.Add("None", 0);

                comboBox1.BeginUpdate();
                comboBox1.DataSource = new BindingSource(CBFilteredList, null);
                comboBox1.DisplayMember = "Key";
                comboBox1.ValueMember = "Value";

                comboBox1.DroppedDown = show;
                comboBox1.SelectedIndex = -1;
                comboBox1.Text = orgText;
                comboBox1.Select(comboBox1.Text.Length, 0);
                comboBox1.EndUpdate();
                Cursor.Current = Cursors.Default;

                ComboBoxBusy = false;
            }
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (ComboBoxBusy == false)
            {
                FilterList(false);
            }
        }

        private void comboBox1_TextUpdate(object sender, EventArgs e)
        {
            FilterList(true);
        }
    }
 }