pdf is not showing correct hindi.

I am using itextsharp.dll hindi in pdf is not showing correctly.

Code

HttpResponse response = HttpContext.Current.Response;
response.Clear();
response.Buffer = true;
response.Charset = "";
response.Cache.SetCacheability(HttpCacheability.NoCache);
response.ContentType = "application/octet-stream";
response.AddHeader("Content-Disposition", "attachment;filename=Service_History.pdf");
response.ContentEncoding = System.Text.Encoding.Unicode;
Document document = new Document();
PdfWriter.GetInstance(document, response.OutputStream);
document.Open();
using (StringWriter sw = new StringWriter())
{
using (HtmlTextWriter htw = new HtmlTextWriter(sw))
{
StringReader sr = new StringReader(sw.ToString());
iTextSharp.text.Document pdfDoc = new Document(PageSize.A4, 60f, 60f, 50f, 10f);
HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
PdfWriter.GetInstance(pdfDoc, response.OutputStream);
pdfDoc.Open();
// BaseFont bf = BaseFont.CreateFont(Environment.GetEnvironmentVariable("windir") + @"\fonts\Utsaah.TTF", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
// BaseFont bf = BaseFont.CreateFont(Environment.GetEnvironmentVariable("windir") + @"\fonts\Mangal.TTF", BaseFont.IDENTITY_H, true);
BaseFont bf = BaseFont.CreateFont(Environment.GetEnvironmentVariable("windir") + @"\fonts\ARIALUNI.TTF", BaseFont.IDENTITY_H, true);
PdfPTable table = new PdfPTable(dt_excel.Columns.Count);
table.WidthPercentage = 100;
table.HorizontalAlignment = 1;