Hi,
i have added see in bold , and now is working...
thanks to pointing me in the right direction 
---
Private Sub et_TextChanged (Old As String, New As String)
    lv.Clear
    If lv.Visible = False Then lv.Visible = True
    If New.Length < MIN_LIMIT Then Return
    Dim str1, str2 As String
    str1 = New.ToLowerCase
    If str1.Length > MAX_LIMIT Then
        str2 = str1.SubString2(0, MAX_LIMIT)
    Else
        str2 = str1
    End If
    AddItemsToList(prefixList.Get(str2), str1)
    AddItemsToList(substringList.Get(str2), str1)
    lv.BringToFront
End Sub