change printer from c# , print via coding in asp.net , print without dialog box in asp.net c#

using System.Drawing.Printing;
using System.Drawing;
using System.Windows.Forms;


  PrintDocument pdoc = null;


    protected void Page_Load(object sender, EventArgs e)
    {
     
        print();
    }

 public void print()
    {
        PrintDialog pd = new PrintDialog();
        pdoc = new PrintDocument();
        pdoc.PrinterSettings.PrinterName = "Samsung SCX-3200 Series";

        PrinterSettings ps = new PrinterSettings();
        Font font = new Font("Courier New", 15);


        PaperSize psize = new PaperSize("Custom", 100, 200);
        //ps.DefaultPageSettings.PaperSize = psize;



        pd.Document = pdoc;
        pd.Document.DefaultPageSettings.PaperSize = psize;
        //pdoc.DefaultPageSettings.PaperSize.Height =320;
        pdoc.DefaultPageSettings.PaperSize.Height = 400;

        pdoc.DefaultPageSettings.PaperSize.Width = 314;

        pdoc.PrintPage += new PrintPageEventHandler(pdoc_PrintPage);

       // pdoc.Print();

        DialogResult result = pd.ShowDialog();
        if (result == DialogResult.OK)
        {
            PrintPreviewDialog pp = new PrintPreviewDialog();
            pp.Document = pdoc;
            result = pp.ShowDialog();
            if (result == DialogResult.OK)
            {
                pdoc.Print();
            }
        }

    }



void pdoc_PrintPage(object sender, PrintPageEventArgs e)
        {
            Graphics graphics = e.Graphics;
            Font font = new Font("Courier New", 10);
            float fontHeight = font.GetHeight();
            int startX = 50;
            int startY = 55;
            int Offset = 40;
            graphics.DrawString("Welcome to MSST", new Font("Courier New", 14), new SolidBrush(Color.Black), startX, startY + Offset);
            Offset = Offset + 20;
            graphics.DrawString("Ticket No:" + your.TicketNo, new Font("Courier New", 14), new SolidBrush(Color.Black), startX, startY + Offset);
            Offset = Offset + 20;
            graphics.DrawString("Ticket Date :" + your.ticketDate, new Font("Courier New", 12), new SolidBrush(Color.Black), startX, startY + Offset);
            Offset = Offset + 20;
            String underLine = "------------------------------------------";
            graphics.DrawString(underLine, new Font("Courier New", 10), new SolidBrush(Color.Black), startX, startY + Offset);

            Offset = Offset + 20;
            String Source= this.source;
            graphics.DrawString("From "+yourSource+" To "+yourDestination, new Font("Courier New", 10), new SolidBrush(Color.Black), startX, startY + Offset);

            Offset = Offset + 20;
            String Grosstotal = "Total Amount to Pay = " + this.amount;

            Offset = Offset + 20;
            underLine = "------------------------------------------";
            graphics.DrawString(underLine, new Font("Courier New", 10), new SolidBrush(Color.Black), startX, startY + Offset);
            Offset = Offset + 20;

            graphics.DrawString(Grosstotal , new Font("Courier New", 10), new SolidBrush(Color.Black), startX, startY + Offset);
            Offset = Offset + 20;
            String DrawnBy = this.drawnBy;
            graphics.DrawString("Conductor - "+yourDrawnBy, new Font("Courier New", 10), new SolidBrush(Color.Black), startX, startY + Offset);





        }