help needed in fizzlerEx and HtmlAgilityPack

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.NET3.0

C#

.NET

jQuery

I am using visual studio 2010 i am using httpwebrequest and httpwebresponse to get page source and for crawling the webpage i am using htmlagilitypack
I want to using :eq selector to reterive data from page source i have found out this can be done using fizzlerEx

http://fizzlerex.codeplex.com/[^]
Example give in the website

using HtmlAgilityPack;
using Fizzler.Systems.HtmlAgilityPack;

var web = new HtmlWeb();
var document = web.Load("http://example.com/page.html")
var page = document.DocumentNode;

foreach(var item in page.QuerySelectorAll("div.item"))
{
    var title = item.QuerySelector("h3:not(.share)").InnerText;
    var date = DateTime.Parse(item.QuerySelector("span:eq(2)").InnerText);
    var description = item.QuerySelector("span:has(b)").InnerHtml;
}

and i am trying the same

var page123 = doc.DocumentNode;
                foreach(var item in page123.QuerySelectorAll("body"))
                {                    
                    var date = item.QuerySelector("b:eq(10)");
                }

but i am getting error
"Unknown functional pseudo 'eq'. Only nth-child is supported."
please can any body help me with problem.