grid view inside datalist

Question

here is my aspx code:

 

<asp:DataList ID="DataList1" runat="server" style="text-align: center" OnItemDataBound="DataList1_ItemDataBound">

<ItemTemplate>

<div style="text-align: justify">

<asp:Label ID="Label7" runat="server" style="text-align: center" Text="Invoice"></asp:Label>

<br />

DATE:

<asp:Label ID="Label3" runat="server" Text='<%#Eval("tdate") %>'></asp:Label>

<br />

<asp:Image ID="Image1" runat="server" Height="86px" Width="97px" />

<br />

ORDER ID:<asp:Label ID="Label4" runat="server" Text='<%#Eval("orderid") %>'></asp:Label>

<br />

</div>

<asp:GridView ID="GridView1" runat="server" Height="131px" Width="504px" AutoGenerateColumns="False" >

<Columns>

<asp:BoundField DataField="itemname" HeaderText="itemname" SortExpression="itemname" />

<asp:BoundField DataField="itemcost" HeaderText="itemcost" SortExpression="itemcost" />

<asp:BoundField DataField="qty" HeaderText="qty" SortExpression="qty" />

<asp:BoundField DataField="subtotal" HeaderText="subtotal" SortExpression="subtotal" />

<asp:BoundField DataField="cname" HeaderText="cname" SortExpression="cname" />

</Columns>

</asp:GridView>

TOTAL:<asp:Label ID="Label5" runat="server" text='<%#Eval("total") %>'></asp:Label>

<br />

<br />

SIGNATURE:<asp:Label ID="Label8" runat="server" Text="Canteen Authority"></asp:Label>

<br />

<br />

<asp:Button ID="Button1" runat="server" Text="GENERATE PDF" />

</ItemTemplate>

</asp:DataList>

 

here is .cs code:

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data;

using System.Data.SqlClient;

using iTextSharp.text;

using System.IO;

using iTextSharp.text.html.simpleparser;

using iTextSharp.text.pdf;

using System.Configuration;

namespace yummyproject

{

public partial class myorder : System.Web.UI.Page

{

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());

string sid;

string orderid;

protected void Page_Load(object sender, EventArgs e)

{

if (Session["Username"] != null)

{

sid = Session["Username"].ToString();

string sql = "SELECT orderid,tdate,total from order1 where sid='" + sid + "' and deliverystatus='notyet'";

SqlDataAdapter da = new SqlDataAdapter(sql, con);

DataTable dt = new DataTable();

da.Fill(dt);

DataList1.DataSource = dt;

DataList1.DataBind();

string qry = "SELECT orderid,tdate,total from order1 where sid='" + sid + "' and deliverystatus='notyet'";

SqlCommand cmd = new SqlCommand(qry, con);

SqlDataReader rdr = cmd.ExecuteReader();

while (rdr.Read())

{

orderid = rdr["orderid"].ToString();

}

}

else

{

Response.Write("nothing");

}

}

protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)

{

GridView GridView1 = (GridView)e.Item.FindControl("GridView1");

BindGrid(GridView1, DataList1.DataKeys[e.Item.ItemIndex].ToString());

}

private void BindGrid(GridView GridView, string CusState)

{

string sql ="SELECT * from orderdetail where orderid='" + orderid + "'";

SqlDataAdapter da = new SqlDataAdapter(sql, con);

DataTable dt = new DataTable();

da.Fill(dt);

GridView.DataSource = dt;

GridView.DataBind();

}

}

}

 

im getting an error