Imports System.IO

Public Class Form1

Private Sub btnList_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnList.Click
' Get the files.
lstFiles.Items.Clear()
Dim dir_info As New DirectoryInfo(txtDir.Text)
For Each file_info As FileInfo In dir_info.GetFiles(cboPattern.Text)
lstFiles.Items.Add(file_info.Name)
Next file_info
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
txtDir.Text = Nothing
End Sub