How to clear a highlighted color of a picturebox image?

[WomanPro]

Hello everyone, I have a simple trouble, I have a button that in click event highlights an image of a picture box.
And I want when I click on the picture box, the image contained not to be highlighted. How can I do that?

Structure RectanglePointF
Public pnt1 As PointF
Public pnt2 As PointF
Public pnt3 As PointF
Public pnt4 As PointF
End Structure
Public LocalMousePosition As Point
Dim graphics As System.Drawing.Graphics

Dim g As System.Drawing.Graphics
Dim brsh As SolidBrush
Dim Highlighted As Boolean = False



Dim PointF_RectOut As New RectanglePointF

Private Sub HighlightPicture_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles HighlightPicture.Click
graphics = PB.CreateGraphics()

g = PB.CreateGraphics()
With PointF_RectOut.pnt1
.X = Convert.ToSingle(216)
.Y = Convert.ToSingle(268)
End With

With PointF_RectOut.pnt2
.X = Convert.ToSingle(16)
.Y = Convert.ToSingle(268)
End With
With PointF_RectOut.pnt3
.X = Convert.ToSingle(16)
.Y = Convert.ToSingle(76)
End With

With PointF_RectOut.pnt4
.X = Convert.ToSingle(216)
.Y = Convert.ToSingle(76)
End With

Dim ptsFArray As PointF() = {PointF_RectOut.pnt1, PointF_RectOut.pnt2, PointF_RectOut.pnt3, PointF_RectOut.pnt4}
g = PB.CreateGraphics()
brsh = New SolidBrush(Color.FromArgb(130, 255, 255, 0))
g.FillPolygon(brsh, ptsFArray)
brsh.Dispose()
End Sub

I tried
Private Sub PB_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles PB.Click
g.Clear(Color.FromArgb(0, 255, 255, 100))

End Sub

I don't know how to do it. Any suggestions?
Any help will be much appreciated.

Thank you so much in advanced.