Drawing Lines In VB 2005

[BarryM]

Iv got a panel on the main form which is set to auto scroll. In the panel there is a picture box that i draw lines in. the lines work perfectly fine until the scroll bar comes up. The picture box expands in the scrollable panel but the program wont allow the lines to continuing drawing(vb 2005)

here's the coding
[coding]
Public Class Form1

Dim DrawGraphics As Graphics
Dim DrawBitmap As Bitmap

Dim y2 As Integer
Dim x2 As Integer = 10
Dim y1 As Integer = 0
Dim x1 As Integer = 0
Dim score As Integer
Dim avg As New ListBox

Private Sub btnenter_Click( ByVal sender As System.Object, ByVal e As System.EventArg s) Handles btnenter.Click
'picgra.Width = x2 + 25
' the value of the score on the grapgh is y2

picgra.Width = x2 + 30
y2 = System.Convert. ToInt64(txtscor e.Text)
x2 = x1 + 10
y2 = y2 * 2
avg.Items.Add(s core)
DrawGraphics.Dr awLine(Pens.Lig htGreen, x1, y1, x2, y2)
picgra.Image = DrawBitmap
y1 = y2
x1 = x2
Me.Text = x2



End Sub

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As System.EventArg s) Handles MyBase.Load
'lblsize.Width = pnl1.Width
'picgra.Width = pnl1.Width
tmrdraw.Start()
tmrdraw.Interva l = 1
DrawBitmap = New Bitmap(picgra.W idth, picgra.Height)
DrawGraphics = Graphics.FromIm age(DrawBitmap)
picgra.Image = DrawBitmap

End Sub


Private Sub Button1_Click(B yVal sender As System.Object, ByVal e As System.EventArg s) Handles Button1.Click
picgra.Width = 600
' DrawGraphics.Dr awLine(Pens.Lig htGreen, 0, 0, 600, 150)
'picgra.Image = DrawBitmap
End Sub
End Class
[/code]
if you have any idea on how i could fix it please post and i dont want to resort to having to import seperate programs into vb