write pdf through memory stream content not writing

iTextSharp.text.Document doc = new iTextSharp.text.Document(iTextSharp.text.PageSize.SMALL_PAPERBACK, 10, 10, 42, 35);
iTextSharp.text.pdf.PdfWriter wri1 = iTextSharp.text.pdf.PdfWriter.GetInstance(doc, memStream);
doc.Open();//Open Document to write
iTextSharp.text.Paragraph paragraph1 = new iTextSharp.text.Paragraph("memStream.EndWrite()");

iTextSharp.text.Phrase pharse = new iTextSharp.text.Phrase("This is my second line using Pharse.");
iTextSharp.text.Chunk chunk = new iTextSharp.text.Chunk(" This is my third line using Chunk.");

doc.Add(paragraph1);

//doc.Add(pharse);

//doc.Add(chunk);
doc.Close();

byte[] content = memStream.ToArray();

// Write out PDF from memory stream. 
using (FileStream fs = File.Create("D:\\Test.pdf"))
{
	fs.Write(content, 0, (int)content.Length);
}