Public Class Form1
    Inherits System.Windows.Forms.Form

    Dim outp As IO.StreamWriter
    Dim inp1 As IO.StreamReader


#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents lstCopy As System.Windows.Forms.ListBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.lstCopy = New System.Windows.Forms.ListBox
        Me.SuspendLayout()
        '
        'lstCopy
        '
        Me.lstCopy.Location = New System.Drawing.Point(32, 16)
        Me.lstCopy.Name = "lstCopy"
        Me.lstCopy.Size = New System.Drawing.Size(312, 238)
        Me.lstCopy.TabIndex = 0
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(432, 465)
        Me.Controls.Add(Me.lstCopy)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

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

        Dim cnt As Integer
        Dim strLine As String
        If Not IO.File.Exists("somejunk.txt") Then
            outp = IO.File.CreateText("somejunk.txt")

            For cnt = 1 To 100
                outp.Write(cnt.ToString.PadLeft(5))  ' pad left helps to put things in columns
                outp.WriteLine((" " & cnt ^ 2).PadLeft(7))

            Next cnt
            outp.Close()
        Else
            MsgBox("oops, file already exists")
            outp = IO.File.AppendText("somejunk.txt")

            For cnt = 101 To 200
                outp.Write(cnt.ToString.PadLeft(5))  ' pad left helps to put things in columns
                outp.WriteLine((" " & cnt ^ 2).PadLeft(7))

            Next cnt
            outp.Close()
        End If

        ' either way, the file exists now
        inp1 = IO.File.OpenText("somejunk.txt")
        Do Until inp1.Peek() = -1  ' end of file
            strLine = inp1.ReadLine()
            lstCopy.Items.Add(strLine)
        Loop
        inp1.Close()
        lstCopy.SelectedIndex = 0 ' default the selection to the first item

    End Sub

    Private Sub lstCopy_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstCopy.SelectedIndexChanged
        Dim strLine As String
        strLine = lstCopy.SelectedItem
        strLine = strLine.Trim
        Dim num As Integer
        Dim sq As Integer
        Dim blankpos As Integer = strLine.IndexOf(" "c)
        num = Convert.ToInt32(strLine.Substring(0, blankpos))
        sq = Convert.ToInt32(strLine.Substring(blankpos).Trim())
        Dim cube As Integer = num * sq
        MsgBox(num & " squared is: " & sq & " and cubed is: " & cube)
    End Sub
End Class