Imports System.IO, System.Collections.Specialized
Public Class Form1
 
 
    Private Sub txtSuchen_TextChanged(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles txtSuchen.TextChanged
        If txtSuchen.Text = String.Empty Then Exit Sub 'Wenn keine Zeile 
        ' angegeben ist.
        If txtPfad.Text = String.Empty Then Exit Sub 'Was soll man denn dann 
        ' auslesen?
        Dim c As New StringCollection, sw As New StreamReader(txtPfad.Text)
        Do While sw.Peek > -1
            c.Add(sw.ReadLine)
        Loop
        If CInt(txtSuchen.Text) > c.Count Then Exit Sub 'So viele Zeilen hat 
        ' die Datei nicht.
        txtAnzeige.Text = c(CInt(txtSuchen.Text) - 1)
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim datei As String = txtAnzeige.Text
        Process.Start(datei)
    End Sub
End Class