C Scrollview scroll up or scroll down

private int oldY = -1;
        private void vScrollBarReport_ValueChanged(object sender, EventArgs e)
        {
            //MessageBox.Show(vScrollBarReport.Value + "");
            // Scroll up , Show menu 
            if (vScrollBarReport.Value < oldY)
            {
                // Scroll down , The hidden menu 
                msReport.Visible = true;
                Invalidate();
            }
            else
            {
                msReport.Visible = false;
            }
            oldY = vScrollBarReport.Value;
        }