Display comboBox "Value" rather than "Text"

Hi
I have a comboBox which has the following Text & Values

Text                     Value
Number 1           one
Number 2           two

When I display the comboBox it displays "Number 1" &  "Number 2" . When I Click on Number 1 I want "one" to be returned to the comboBox Text. This seems to happen momentarily but it reverts back to "Number 1". Appreciate any input into what I am doing wrong. See code below:

regards
Pat

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
                Item item = comboBox1.Items[comboBox1.SelectedIndex] as Item;
                comboBox1.Text = item.Value.ToString();
         }

        private void Form1_Load(object sender, EventArgs e)
        {
            comboBox1.Items.Add(new Item("one" , "Number 1"));
            comboBox1.Items.Add(new Item("two" , "Number 2"));
            comboBox1.SelectedIndexChanged += new EventHandler (comboBox1_SelectedIndexChanged);
        }
    }
}

public class Item
{
    public Item(string value, string text) { Value = value; Text = text; }
    public string Value { get; set; }
    public string Text { get; set; }
   
    public override string ToString() { return Text; }
}