protected void Button2_Click(object sender, EventArgs e)
{
String pathin = "E:\\pdf\\so\\22.pdf";
String pathout = "E:\\pdf\\so\\1rere.pdf";
PdfReader reader = new PdfReader(pathin);
PdfStamper stamper = new PdfStamper(reader, new FileStream(pathout, FileMode.Create));
PdfContentByte pbover = stamper.GetOverContent(1);
string text = "<ol>
<li><span style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 16.12px; orphans: auto; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: 1; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: rgb(255, 255, 255);">Avul Pakir Jainulabdeen "<strong>A. P. J." Abdul Kalam</strong> was the 11th President of India from 2002 to 2007. <strong><em>Rameswaram</em></strong>, Tamil Nadu, and studied physics</span></li>
</ol>
<ul>
";
ColumnText ct = new ColumnText(pbover);
ct.SetSimpleColumn(new Phrase(new Chunk(text, FontFactory.GetFont(FontFactory.HELVETICA, 9, Font.NORMAL))),
46, 190, 530, 36, 25, Element.ALIGN_LEFT | Element.ALIGN_TOP);
ct.Go();
stamper.Close();
}