how to use MS paint line command in PictureBox using VB.net Window Form Applicatoin

Public Class Form1

    'This flag keeps track of wether we have started to draw a line or not
    'if this is the first time the mouse was clicked in the picturebox then the flag value is FALSE
    'if this is the second time the mouse was clicked in the picturebox then the flag value is TRUE
    Dim Drawing As Boolean

    'This flag stores the mousepointer location(SPoint stands for STARTPoint for the line and is X,Y values)
    Dim SPoint As Point

    'This flag stores the mousepointer location(EPoint stands for ENDPoint for the line and is X,Y values)
    Dim EPoint As Point

    'This is the history of the lines drawn so far
    'HistorySPoint stores the line STARTING points
    'HistoryEPoint stores the line END points
    Dim HistorySPoint As Generic.List(Of Point)
    Dim HistoryEPoint As Generic.List(Of Point)

    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        'Tidy up the form level/scope variables
        Drawing = Nothing
        SPoint = Nothing
        EPoint = Nothing
        HistoryEPoint = Nothing
        HistorySPoint = Nothing
    End Sub


    'FormLoad Event
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'we set the label to ready to let the user know we are ready
        Label1.Text = "Ready"
        'we initailise as new STARTPoints collection
        HistorySPoint = New Generic.List(Of Point)
        'we initailise as new ENDPoints collection
        HistoryEPoint = New Generic.List(Of Point)
        'show info
        MsgBox("To draw a line, click in the picturebox to define a START point" & vbCrLf & "then click again elsewhere to define an END point" & vbCrLf & "On the second click the line will be drawn and listed in the history" & vbCrLf & "To remove a line click on the line in the listbox and then click on the UNDO button.", MsgBoxStyle.Information, "Information.")
    End Sub


    'DrawLineProcedure - This passes the PENcolor as a parameter
    Private Sub DrawLine(ByVal color As System.Drawing.Pen)
        'Define a graphics context/canvas (drawing surface)
        Dim TheGrafix As System.Drawing.Graphics
        'Assign the picturebox context/canvas to the drawing surface
        TheGrafix = PictureBox1.CreateGraphics()
        'draw the line on the picturebox canvas 
        'using the PENcolor and the STARTPoint and the ENDPoint of the line
        TheGrafix.DrawLine(color, SPoint, EPoint)
        'Yidy up after ourselves
        TheGrafix.Dispose()
    End Sub



    Private Sub PictureBox1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseClick
        'If this is the START of a newline then Drawing is always FALSE
        'If we have started to draw a line previously with a mouse click then Drawing is always TRUE
        'at the end of drawing every line Drawing is reset to FALSE - ready for another line
        If Not Drawing Then
            'as we are startinga line - set the flag to show as much
            Drawing = True
            SPoint.X = e.X      'store the mouse X coords in POINT SPoint
            SPoint.Y = e.Y      'store the mouse Y coords in POINT SPoint
            'update the label to show wehave started to draw a new line
            Label1.Text = "Start point mapped, please move mouse to end point and click again"
        Else

            EPoint.X = e.X      'store the mouse X coords in POINT EPoint
            EPoint.Y = e.Y      'store the mouse Y coords in POINT EPoint
            'Store both the START and END pooints in the history 
            HistorySPoint.Insert(ListBox1.Items.Count, SPoint)
            HistoryEPoint.Insert(ListBox1.Items.Count, EPoint)
            'Add the points to our history listbox for visual confirmation
            ListBox1.Items.Insert(ListBox1.Items.Count, "(" & SPoint.X & ", " & SPoint.Y & ") - (" & EPoint.X & ", " & EPoint.Y & ")")
            'Physically draw the line by calling the DRAWLINE procedure whilst passing a PENColor
            'in this case the color is Black
            DrawLine(Pens.Black)
            'update the label to show we are ready for the next line
            Label1.Text = "Ready"
            'Reset the Drawing Flag to FALSE
            Drawing = False
        End If
    End Sub

    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        'Echo the mouse co-ordinates in the label
        Label2.Text = "X: " & e.X
        Label3.Text = "Y: " & e.Y
    End Sub

    Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        'THe user has clicked on an line inthe HISTORY listory so ENABLE the UNDO button
        'to allow the user to UNDO the selected line
        If ListBox1.SelectedIndex <> (-1) Then Button1.Enabled = True
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'The user clicked the undo button
        'Redraw all the lines black EXCEPT the selected line 
        'which is drawn in the same color as the Picturebox BACKCOLOR
        'and after that REMOVE the line details from the Points history and the history listbox
        Dim intCounta As Integer
        Dim intSelIdx As Integer
        intSelIdx = ListBox1.SelectedIndex
        ListBox1.Items.RemoveAt(intSelIdx)
        If HistorySPoint.Count > 0 Then
            For intCounta = 0 To HistorySPoint.Count - 1
                If intCounta = intSelIdx Then
                    SPoint = HistorySPoint(intCounta)
                    EPoint = HistoryEPoint(intCounta)
                    DrawLine(Pens.White)
                Else
                    SPoint = HistorySPoint(intCounta)
                    EPoint = HistoryEPoint(intCounta)
                    DrawLine(Pens.Black)
                End If
            Next
            HistorySPoint.RemoveAt(intSelIdx)
            HistoryEPoint.RemoveAt(intSelIdx)
        End If
        intSelIdx = Nothing
        intCounta = Nothing
    End Sub

End Class