The Third party app... deleting all the sessions and cookies
but I got the solution.
On First page C# Code:
DataSet dsinfo = new DataSet();
dsinfo.Tables.Add(dtInfo);
XmlDataDocument xmldatainfo = new XmlDataDocument(dsinfo);
XmlElement xmlElementinfo = xmldatainfo.DocumentElement;
string xml_stringinfo = xmldatainfo.OuterXml.ToString();
Session["dtInfo"] = xml_stringinfo;
On third Party page Passing Hidden input
Like this: under form tag
<input type="hidden" name="FeeDetailinfo" value="<%=Session["dtInfo"] %>" />
and one third page retrieve the input in c# code
Like this:
DataTable dtinfo = new DataTable();
DataSet dsinfo = new DataSet();
StringReader readerinfo = new StringReader(Request.Form["FeeDetailinfo"]);
dsinfo.ReadXml(readerinfo);
dtinfo = dsinfo.Tables[0];