how to use a HscrollBar

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            PictureBox1.Image = Image.FromFile(OpenFileDialog1.FileName)
            HScrollBar1.Maximum = PictureBox1.Image.Width - _
            PictureBox1.Width + HScrollBar1.Height
            VScrollBar1.Maximum = PictureBox1.Image.Height - _
            PictureBox1.Height + VScrollBar1.Width
            VScrollBar1.Enabled = True
            HScrollBar1.Enabled = True
            If PictureBox1.Height > PictureBox1.Image.Height Then
                VScrollBar1.Enabled = False
            End If
            If PictureBox1.Width > PictureBox1.Image.Width Then
                HScrollBar1.Enabled = False
            End If
        End If
    End Sub

Private Sub HScrollBar1_Scroll(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles HScrollBar1.Scroll
        Dim gph As Graphics = PictureBox1.CreateGraphics
        gph.DrawImage(PictureBox1.Image, New Rectangle(0, 0, PictureBox1.Width - HScrollBar1.Height, _
        PictureBox1.Height - VScrollBar1.Width), _
        New Rectangle(HScrollBar1.Value, VScrollBar1.Value, _
        PictureBox1.Width - HScrollBar1.Height, _
        PictureBox1.Height - VScrollBar1.Width), GraphicsUnit.Pixel)
    End Sub

Private Sub VScrollBar1_Scroll(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles VScrollBar1.Scroll
        Dim gph As Graphics = PictureBox1.CreateGraphics
        gph.DrawImage(PictureBox1.Image, New Rectangle(0, 0, PictureBox1.Width - HScrollBar1.Height, _
        PictureBox1.Height - VScrollBar1.Width), _
        New Rectangle(HScrollBar1.Value, VScrollBar1.Value, _
        PictureBox1.Width - HScrollBar1.Height, _
        PictureBox1.Height - VScrollBar1.Width), GraphicsUnit.Pixel)
    End Sub