generate Barcode asp.net c#

Linear code128 = new Linear();

// Barcode data to encode
code128.Data = txttag.Text;
// Barcode symbology type. Code 128 supports types: CODE128, CODE128A, CODE128B, CODE128C.
code128.Type = BarcodeType.CODE128;
// Apply checksum digit for Code-128
code128.AddCheckSum = true;

/*
* Barcode Image Related Settings
*/
// Unit of meature for all size related setting in the library. 
code128.UOM = UnitOfMeasure.PIXEL;
// Bar module width (X), default is 1 pixel;
code128.X = -5;
// Bar module height (Y), default is 60 pixel;
code128.Y = 15;

// Barcode image left, right, top, bottom margins. Defaults are 0.
code128.LeftMargin = 0;
code128.RightMargin = 0;
code128.TopMargin = 0;
code128.BottomMargin = 0;
// Image resolution in dpi, default is 72 dpi.
code128.Resolution = 72;
// Created barcode orientation.
//4 options are: facing left, facing right, facing bottom, and facing top
code128.Rotate = Rotate.Rotate0;

/*
* Linear barcodes human readable text styles
*/
// Display human readable text under the barcode
code128.ShowText = true;
// Display checksum digit at the end of barcode data.
code128.ShowCheckSumChar = true;
// Human readable text font size, font family and style
code128.TextFont = new Font("Arial", 9f, FontStyle.Regular);
// Space between barcode and text. Default is 6 pixel.
code128.TextMargin = 3;

// Generate Code-128 and encode barcode to gif format
code128.Format = System.Drawing.Imaging.ImageFormat.Png;
code128.drawBarcode("D:\\" + txttag.Text + ".png");

//   DataSet ds = Objcl.AddTag(txttag.Text, Convert.ToByte(code128.drawBarcode()), 20);
}