Print panel in C# windows application

private void doc_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
    Panel grd = new Panel();
    Bitmap bmp = new Bitmap(grd.Width, grd.Height, grd.CreateGraphics());
    grd.DrawToBitmap(bmp, new Rectangle(0, 0, grd.Width, grd.Height));
    RectangleF bounds = e.PageSettings.PrintableArea;
    float factor = ((float)bmp.Height / (float)bmp.Width);
    e.Graphics.DrawImage(bmp, bounds.Left, bounds.Top, bounds.Width, factor * bounds.Width);
}

private void button1_Click_1(object sender, EventArgs e)
       {
           System.Drawing.Printing.PrintDocument doc = new System.Drawing.Printing.PrintDocument();
           doc.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(doc_PrintPage);
           doc.Print();
       }