FileStream MyFileStream = new FileStream(@"d:inetpubwwwrootsmall.pdf", FileMode.Open);
long FileSize;
FileSize = MyFileStream.Length;
byte[] Buffer = new byte[(int)FileSize];
MyFileStream.Read(Buffer, 0, (int)MyFileStream.Length);
MyFileStream.Close();
Response.ContentType="application/pdf";
Response.AddHeader( "content-disposition","attachment; filename=MyPDF.PDF");
Response.BinaryWrite(Buffer);