drawing on a panel using lineshape with vbnet 2010

Question

I have a vbnet app that has a lineshape (Line1) located in a panel (Panel1)

I want to draw line1 using panel1's mousedown - mousemove and mouseup.

I can get line1 to start and stop where I want and it becomes visible on mouseup

but would like it to be visible during mousemove.

I am using vbnet express 2010 on windows 8

Here is my code

Public Class Form1

Dim LoadPic As String

Private startX As Integer 'start position x of line

Private startY As Integer 'start position y of line

Private isMouseDown As Boolean = False 'recognize mouse down or up

Private Sub btnLoad_Click(sender As System.Object, e As System.EventArgs) Handles btnLoad.Click

FD1.ShowDialog()

LoadPic = FD1.FileName

Panel1.BackgroundImage = Image.FromFile(LoadPic)

End Sub

Private Sub Panel1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseDown

Line1.Visible = True

startX = e.X

startY = e.Y

End Sub

Private Sub Panel1_mousemove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseMove

If isMouseDown = True Then

Line1.X1 = startX

Line1.Y1 = startY

Line1.X2 = e.X

Line1.Y2 = e.Y

End If

End Sub

Private Sub Panel1_MouseUp(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseUp

Line1.X1 = startX

Line1.Y1 = startY

Line1.X2 = e.X

Line1.Y2 = e.Y

End Sub

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

Line1.Visible = False

End Sub

End Class