C#

// assume all three NumericUpDowns have "Minimum" and "Maximum"
// values set to: Decimal.MinValue, and Decimal.MaxValue
private Func<decimal, decimal, decimal> PE;

private decimal x, y;

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    x = numericUpDown1.Value;
    y = numericUpDown2.Value;

    switch (comboBox1.SelectedIndex)
    {
        case 0: // multiply
            PE = (d1, d2) => d1*d2;
            break;
        case 1: // divide
            // probably better to handle divisor == 0 here ?
            PE = (d1, d2) => d1/ d2;
            break;
        case 2: // power
            // need to handle case of raising to the 0th. power here ?
            // as is: zero to the zeroth. power will be returned as #1 !
            PE = (d1, d2) => (decimal) Math.Pow((double) d1, (double) d2);
            break;
        default:
            // throw error here during development
            break;
    }

    try { numericUpDown3.Value = PE(x, y); }
        // handle System.DivideByZero exception
        catch (DivideByZeroException dZero) { }
        // handle System.Overflow exception: Decimal.MinValue or Decimal MaxValue
        catch (OverflowException oFlow) {}
}

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private Capture capture = null;
        private Filters filters = new Filters();
      

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
           
            capture = new Capture(filters.VideoInputDevices[0], filters.AudioInputDevices[2]);

            //capture.CaptureComplete += new EventHandler(OnCaptureComplete);
            try
            {
                if (capture.PreviewWindow == null)
                {
                    capture.PreviewWindow = panelVideo;
                    // mnuPreview.Checked = true;
                }
                else
                {
                    capture.PreviewWindow = null;
                    // mnuPreview.Checked = false;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("Unable to enable/disable preview. Please submit a bug report.\n\n" + ex.Message + "\n\n" + ex.ToString());
            }
            


        }

        private void button2_Click(object sender, EventArgs e)
        {
            capture.FrameEvent2 += new Capture.HeFrame(CaptureDone);
            capture.GrapImg();
        }
        private void CaptureDone(System.Drawing.Bitmap e)
        {
            this.pictureBox.Image = e;
            capture.FrameEvent2 -= new Capture.HeFrame(CaptureDone);
           // pictureBox.Image.Save("ddd.jpg");
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (!capture.Cued)
                capture.Filename = @"F:\demo.wmv";
            capture.RecFileMode = DirectX.Capture.Capture.RecFileModeType.Wmv;  // Vidow Format is wmv
            capture.Cue();
            capture.Start();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            capture.Stop();
        }
    }
}