'define a class containing the document info
Public Class CDocument
    Public ID As Long
    Public FileName As String
    Public DocType As String
        
    Public Sub New(ByVal idf As Long, ByVal FN As String,_
        ByVal DT As String)
        ID = idf
        FileName = FN
        DocType = DT
    End Sub

    Public Overrides Function ToString() As String
       Return FileName + " (" + DocType + ")"
    End Function
End Class

Public Sub FillDocumentList(ByVal IDMask As Integer)
    Dim i As Integer
    listDoc.Items.Clear()
	
    For i = 1 To 20
	 listDoc.Items.Add(New CDocument(i.ToString(), _
         "File " + i.ToString() + ".txt", "txt")
    Next
End Sub

Private Sub listDoc_SelectedIndexChanged(ByVal sender _
    As System.Object, ByVal e As System.EventArgs) _
    Handles listDoc.SelectedIndexChanged
    Dim d As CDocument
    d = listDoc.SelectedItem
      
    MessageBox.Show("Document ID : " + d.ID.ToString() + vbCrLf +_
          "Document name : " + d.FileName + vbCrLf +_
          "Doc Type : " + d.DocType + vbCrLf)
End Sub