Combobox Event Handlers

I have a combobox and a txtbox. Both are databound. Choosing a value in the combobox initiates the txtbox fill. Right now my event handle for this event is "onclick" but I would like to change the event to something that would initiate the txtbox fill "onmouseover". I tried "mouseHover" but that does not work. Any ideas?

Code:

---

Region "Fill Description Box"
    Private Sub cboPartNumber_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cboPartNumber.MouseHover
        Dim UdtConn As New SqlConnection(sBoMConnectionString)

        'Selects a part numbers corresponding description'
        Using UdtConn
            UdtConn.Open()
            Dim udtSqlCmd As New SqlCommand("SELECT Part_Desc FROM dbo.Part WHERE Part_Nbr = @Part_Number", UdtConn)
            udtSqlCmd.Parameters.AddWithValue("@Part_Number", cboPartNumber.Text)
            Dim myReader As SqlDataReader = udtSqlCmd.ExecuteReader

            If myReader.HasRows Then
                Do While myReader.Read
                    txtPartPickDescription.Text = myReader.GetValue(0)
                Loop
            End If
            UdtConn.Close()
        End Using
    End Sub
#End Region

---

Thank you for any help you may offer.

Perhaps this article may be of help :

Extending the ComboBox with C#
http://www.codeguru.com/csharp/cshar...cle.php/c15261

It is in C# though, but it covers more advanced topics about the ComboBox.