Sub chkb1_SelectedIndexChanged(sender As Object, e As EventArgs)
    dim sb as new stringbuilder()
    dim i as integer

    for i=0 to chkb1.items.count -1
        if chkb1.items(i).Selected  then
            sb.append(i)
            sb.append(" - ")
            sb.append(chkb1.Items(i).text)
            sb.append("<br>")
        end if
    next

    lchkbox.text = sb.ToString()

End Sub