AddItem and RemoveItem for Listboxes in Access 97/2000

Access XP and 2003 listboxes already have these methods. I made 2 functions which manipulate Listbox’ RowSource property. You have to set Listbox Row Source Type property to Value List and then you can add items using:
ListBox1.RowSource = AddItem(ListBox1.RowSource, "key1" & ";" & "New Item", 0)
And remove:
ListBox1.RowSource = RemoveItem(ListBox1.RowSource, 0)

These 2 functions assumes, that Listbox has 2 columns. For one-column code version please look at Update for "AddItem and RemoveItem for Listboxes in Access 97/2000"

Public Function RemoveItem(strRowSource As String, _
                    lngItemNum As Integer) As String
    Dim Pos1 As Long, strResult As String, Pos2 As Long
    Dim lngCount As Long, i As Integer

    strResult = strRowSource
    Pos1 = 1
    For i = 0 To lngItemNum
        If (Pos1 > 0) And (i = lngItemNum) Then
            Pos2 = InStr(Pos1 + 1, strRowSource, ";")
            Pos2 = InStr(Pos2 + 1, strRowSource, ";")
            If Pos2 = 0 Then Pos2 = Len(strRowSource)
            strResult = Left(strRowSource, Pos1 - 1)
            If Len(strResult) > 0 Then _
                strResult = strResult & ";"
            strResult = strResult & _
                Mid(strRowSource, Pos2 + 1)
            If Right(strResult, 1) = ";" Then _
                strResult = _
                    Left(strResult, Len(strResult) - 1)
        End If
   
        Pos1 = InStr(Pos1 + 1, strRowSource, ";")
        If Pos1 > 0 Then
            Pos1 = InStr(Pos1 + 1, strRowSource, ";")
        End If
    Next i

    RemoveItem = strResult
End Function
Public Function AddItem(strRowSource As String, _
        strItem As String, _
        lngItemNum As Integer) As String
    Dim Pos1 As Long, strResult As String, Pos2 As Long
    Dim lngCount As Long, i As Integer

    strResult = strRowSource
    Pos1 = 1
    For i = 0 To lngItemNum
        If (Pos1 > 0) And (i = lngItemNum) Then
            strResult = Left(strRowSource, Pos1 - 1)
            If Len(strResult) > 0 Then _
                strResult = strResult & ";"
            strResult = strResult & strItem
            If Len(strResult) > 0 Then _
                strResult = strResult & ";"
            If Pos1 > 1 Then Pos1 = Pos1 + 1
            strResult = strResult & _
                Mid(strRowSource, Pos1)
            If Right(strResult, 1) = ";" Then _
                strResult = _
                    Left(strResult, Len(strResult) - 1)
            Exit For
        End If
   
        Pos1 = InStr(Pos1 + 1, strRowSource, ";")
        If Pos1 > 0 Then
            Pos1 = InStr(Pos1 + 1, strRowSource, ";")
            If Pos1 = 0 Then Pos1 = Len(strRowSource) + 1
        End If
    Next i

    AddItem = strResult
End Function