How about this.

Partial Class test

    Inherits CyrilJohnston.CoreLibrary.WebPage

    Dim cbxlist As New CheckBoxList

    Protected Sub form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles form1.Load

        Dim sitems As New System.Collections.Specialized.StringCollection

        cbxlist.ID = "dynamicCheckBox"

        For i As Integer = 1 To 10

            sitems.Add(i.ToString)

        Next

        cbxlist.DataSource = sitems

        Me.PlaceHolder1.Controls.Add(cbxlist)

        cbxlist.DataBind()

    End Sub

………

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim CheckedIndexes As String = ""

        Dim CheckedText As String = ""

        For i As Integer = 0 To Me.cbxlist.Items.Count - 1

            If Me.cbxlist.Items(i).Selected Then

CheckedIndexes &= "Index=" & Me.cbxlist.Items(i).Value & ControlChars.CrLf

            End If

        Next

        ' Breakpoint here to view

        CheckedIndexes = ""

    End Sub

Rgds,

Martin.