c# - How to add query string param and do the paging -

i trying implement gridview manual paging. want add query string param paging. seo , absolutely required. code published on website , has 500 entries(posts in gridview).

now company wants me querystring param search engine can go through pages , captures it. right search engines seeing page 1 on gridview. thats came know seo team.

i dont have idea on how this. please help. can not change code because mess pages live.

girdview code

<asp:gridview runat="server" allowpaging="true" id="entriesgridview" autogeneratecolumns="false" datakeynames="entryid" showheader="false" onrowdatabound="entriesgridview_rowdatabound" cssclass="grid" onpageindexchanging="entriesgridview_pageindexchanging" pagesize="20"> <pagerstyle cssclass="pager"></pagerstyle>       <columns>             // template / bound fields       </columns>       <emptydatatemplate>             // empty results text....       </emptydatatemplate>       <emptydatarowstyle horizontalalign="center" />    </asp:gridview> 

code-behind

protected void entriesgridview_pageindexchanging(object sender, gridviewpageeventargs e) {       loadentriesgridview(false, false, false, sqlcriteria);       entriesgridview.pageindex = e.newpageindex;       entriesgridview.databind(); } 

datasource

public static entrycollection loadforcriteriawithjoin(string sqlcriteria, bool isemailquery, bool isfullnamequery, string sortexpression)       {             //default sort expression             if (string.isnullorempty(sortexpression)) sortexpression = "orderby";             //create dynamic sql load object             var selectquery = new stringbuilder();             selectquery.append("select");             selectquery.append(" ce.* ");             selectquery.append("from entrytable ce ");             selectquery.append("join contestantstable cc ");             selectquery.append("on ce.contestantid = cc.contestantid ");              string whereclause = null;             if (isemailquery)                   whereclause = "where ce.isapproved = 1 , cc.email = @emailaddress";             else if (isfullnamequery)                   whereclause = "where ce.isapproved = 1 , cc.firstname + ' ' + cc.lastname '%' + @fullname + '%'" +                         "or ce.cname '%' + @fullname + '%'" +                          "or ce.ctitle '%' + @fullname + '%'" +                           "or ce.answer1 + ' ' + ce.answer2 + ' ' + answer3 '%' + @fullname + '%'";             else                   whereclause = "where ce.isapproved = 2";     // returning empty result...              if (!string.isnullorempty(sqlcriteria))                   selectquery.append(whereclause);              selectquery.append(" order " + sortexpression);             var database = t.i.database;             var selectcommand = database.getsqlstringcommand(selectquery.tostring());              if (isemailquery)                   database.addinparameter(selectcommand, "@email", system.data.dbtype.string, sqlcriteria);             if (isfullnamequery)                   database.addinparameter(selectcommand, "@fullname", system.data.dbtype.string, sqlcriteria);              //execute command             var results = new entrycollection();             using (var dr = database.executereader(selectcommand))             {                   while (dr.read())                   {                         var entry = new entry();                         mwcompetitionsentry.loaddatareader(entry, dr);                         results.add(entry);                   }                   dr.close();             }             return results;       }