open image in picturebox in vb.net

 Dim open As New OpenFileDialog()
        open.Filter = "Image Files(*.png; *.jpg; *.bmp)|*.png; *.jpg; *.bmp"
        If open.ShowDialog() = DialogResult.OK Then
            Dim fileName As String = System.IO.Path.GetFullPath(open.FileName)
            PictureBox1.Image = New Bitmap(open.FileName)
            Me.PictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom
        End If