Not declared

Hi,

I get the following error about not being declared;

lstFilesFound

on line that reads

lstFilesFound.Add(f)

Here is the code...

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        searchFiles()

    End Sub

    Private Sub searchFiles()
        Try
            Dim drives() As String
            Dim rootfolders() As String
            Dim d As String
            Dim f As String
            drives = System.IO.Directory.GetLogicalDrives()
            For drivecount As Integer = 0 To drives.Length - 1
                rootfolders = System.IO.Directory.GetDirectories(drives(drivecount))
                For rootFolderCount As Integer = 0 To rootfolders.Length - 1
                    DirSearch(rootfolders(rootFolderCount))
                Next
            Next
        Catch ex As Exception

        End Try
    End Sub

    Sub DirSearch(ByVal sDir As String)
        Dim d As String
        Dim f As String
        Try
            For Each d In System.IO.Directory.GetDirectories(sDir)
                For Each f In System.IO.Directory.GetFiles(d, "*.Txt")
                    lstFilesFound.Add(f)
                Next
                DirSearch(d)
            Next
        Catch excpt As System.Exception
            Debug.WriteLine(excpt.Message)
        End Try
    End Sub
End Class