Displaying data in to Gridview with checkbox option and if i click a button it will display the fancybox.the code is perfectly executing bt its not displaying the Fancybox

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="ProductGrid.aspx.cs" Inherits="ProductGrid" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %>
 <asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <br />
    <asp:Label ID="LblNav" runat="server" Text="Product -" Font-Bold="true" Font-Size ="Small"  ForeColor ="Maroon">
    <asp:Label ID="Label1" runat="server" Text="List Of Products" Font-Bold="true" Font-Size ="X-Small"  ForeColor ="blue">
    <div class="contentHeader">
        <br />
        <br />
        <asp:Label ID="lbllistofprd" Text="List of Products" runat="server" >
        <hr />
    </div>
    <table align="right">
   <%--Added default button--%>
        <tr>
            <td>
                <asp:Button ID="btn_show_ProductDetails" runat="server" Text=" Show Items " CssClass="button" 
           Height="40px" Font-Bold="True"  
           Enabled="False" Width="120px" OnClientClick="return displayFancybox('showproductdetails.aspx');" />
                <%----%>
            </td>
            <td>
       <%--<a id="btn_addProductdetails_link" href="/KB/answers/ProductItemsDetails.aspx"></a>--%>
                <asp:Button ID="btn_addProductDetails" runat="server" Text=" + Add Items " CssClass="button" 
           Height="40px" Font-Bold="True"    
           Enabled="False" Width="120px" OnClientClick="return displayFancybox('ProductItemsDetails.aspx');" />
                <%----%>
            </td>
   <%--<td>
  <a id="various4" href="/KB/answers/ProductItemsDetails.aspx">
       <asp:ImageButton ID="imgaddproductdetails" runat="server" 
           ImageUrl="~/images/add.JPG"  ToolTip="Add Product Details" Width="25px"></a>
   </td>
   --%>
            <td>
                <asp:Button ID="btn_addNewProduct" 
            runat="server" Text="+ Add New Product" CssClass="addButton"
            Font-Bold="True" Height="40px" OnClientClick="return displayFancybox('NewProduct.aspx');" />
            </td>
   <%--<td><a id="various" href="/KB/answers/NewProduct.aspx"><asp:ImageButton ID="Imgaddnewproduct" runat="server" ImageUrl="~/images/addproduct.jpg" ToolTip="Add New Product" Width="35px"></a>
    </td>--%>
            <td>
                <asp:Button ID="btn_delProduct" runat="server" Text=" X Delete " CssClass="button"
            Font-Bold="True" Height="40px"  
            Enabled="False" Width="100px" onclick="btn_delProduct_Click1">
                <asp:ConfirmButtonExtender ID="btn_delProduct_ConfirmButtonExtender" 
            runat="server" ConfirmText="Are you sure to delete product" Enabled="True" TargetControlID="btn_delProduct">
                
            </td>
            <td>
                <asp:Button ID="btnUpdate" 
                    runat="server" Text="Edit" CssClass="button"
            Font-Bold="True" Height="40px" Width="100px" 
                    Enabled="False" OnClientClick="return displayFancybox('NewProduct.aspx?U=');" >
                
            </td>
                      <%--<td><asp:ImageButton ID="imgdelete" runat="server" ImageUrl="~/images/delete.bmp" ToolTip="DELETE" Width="25px" /></td>--%>
        </tr>
    </table>
    <table style="height:100px;  width: 100%; padding:10px;">
        <tr>
            <td align="center">
                <asp:GridView ID="GVProduct" runat="server" AutoGenerateColumns="False" CssClass="datatable "   
               GridLines ="None"  style="margin-right: 50px" CellPadding="4" CellSpacing="1"  
               Font-Size="Small" BackColor="#E6E6E6" ForeColor="#0B3861" 
               AllowPaging="True" PageSize ="15" 
               Width="100%" 
                 onrowcreated="GVProduct_RowCreated" 
               onrowdatabound="GVProduct_RowDataBound" ondatabound="GVProduct_DataBound" 
               onpageindexchanging="GVProduct_PageIndexChanging1" 
               onselectedindexchanged="GVProduct_SelectedIndexChanged" >
                    <%--   onselectedindexchanged="GVProduct_SelectedIndexChanged" >--%>
                    <alternatingrowstyle backcolor="White" />
                    <%--<add by="" naresh="" önpageindexchanging="GVProduct_PageIndexChanging"></add>--%>
                    <columns>
                        <asp:TemplateField ControlStyle-Width="15px" ItemStyle-HorizontalAlign="Center">
                            <HeaderTemplate>
                                Select
                            </HeaderTemplate>
                            <itemtemplate>
                                <asp:CheckBox ID="chkselect" runat="server"  AutoPostBack="true" 
                OnCheckedChanged="chkselect_CheckedChanged" />
                                <asp:MutuallyExclusiveCheckBoxExtender ID="chkselect_MutuallyExclusiveCheckBoxExtender" 
                runat="server" Enabled="True"  Key="gridchk" TargetControlID="chkselect">
                                
                            </itemtemplate>
                            <controlstyle width="15px"></controlstyle>
                        
                        <asp:TemplateField HeaderText="Product Name" ItemStyle-HorizontalAlign="Left">
                            <itemtemplate>
                                <asp:Label ID="productname" Text='<%# Eval("product_name") %>' runat="server" CssClass="paddingItemDes">
                            </itemtemplate>
                        
                        <asp:BoundField DataField="product_description" 
                HeaderText="Product Description" SortExpression="roduct_description" 
              ItemStyle-HorizontalAlign="Left" ItemStyle-CssClass="paddingItemDes" >
                        <itemstyle horizontalalign="Left" cssclass="paddingItemDes"></itemstyle>
                        
                        <%--Added by Raju to enhance the richness of UI--%>
                        <asp:TemplateField HeaderText="In Stock" ItemStyle-HorizontalAlign="Center">
                            <itemtemplate>
                                <asp:Label ID="instock" runat="server"                         
                        Text='<%# Eval("Stock") %>'>
                            </itemtemplate>
                        
                        <asp:TemplateField HeaderText="Committed" ItemStyle-HorizontalAlign="Center">
                            <itemtemplate>
                                <asp:Label ID="committed" runat="server" 
                        Text='<%# Eval("Commited") %>'>
                            </itemtemplate>
                        
                        <asp:TemplateField HeaderText="On Order" ItemStyle-HorizontalAlign="Center">
                            <itemtemplate>
                                <asp:Label ID="onorder" runat="server" 
                        Text='<%# Eval("Inorder") %>'>
                            </itemtemplate>
                        
                        <asp:TemplateField HeaderText="Wholesale" ItemStyle-HorizontalAlign="Center">
                            <itemtemplate>
                                <asp:Label ID="wholesale" runat="server" 
                        Text='<%# Eval("wholesalePrice") %>'>
                            </itemtemplate>
                        
                    </columns>
                    <footerstyle backcolor="#507CD1" font-bold="True" forecolor="White" />
                    <%--    <pagerstyle backcolor="#0078AE" horizontalalign="Right" cssclass="margin5x " />--%>
                    <pagerstyle backcolor="#0078AE" horizontalalign="Right" cssclass="paddingItemDes" width="100%" height="25px" />
                    <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333"/>
                    <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White"/>
                    <editrowstyle backcolor="#0078AE" />
                    <alternatingrowstyle backcolor="White" />
                    <pagertemplate>
                        <asp:LinkButton ID="LinkButton1" runat="server" CommandName="Page" CommandArgument="First" CssClass="Linkbutton">First
                        <asp:Label ID="pmore" runat="server" Text="">
                        <asp:LinkButton ID="LinkButton2" runat="server" CommandName="Page" CommandArgument="Prev" CssClass="Linkbutton">Pre
                        <asp:LinkButton ID="p0" runat="server" CssClass="Linkbutton">LinkButton
                        <asp:LinkButton ID="p1" runat="server" CssClass="Linkbutton">LinkButton
                        <asp:LinkButton ID="p2" runat="server" CssClass="Linkbutton">LinkButton
                        <asp:Label ID="CurrentPage" runat="server" Text="Label"  ForeColor ="#EEE000" Font-Size ="Medium" >
                        <asp:LinkButton ID="p4" runat="server" CssClass="Linkbutton">LinkButton
                        <asp:LinkButton ID="p5" runat="server" CssClass="Linkbutton">LinkButton
                        <asp:LinkButton ID="p6" runat="server" CssClass="Linkbutton">LinkButton
                        <asp:LinkButton ID="LinkButton3" runat="server" CommandName="Page" CommandArgument="Next" CssClass="Linkbutton">Next
                        <asp:Label ID="nmore" runat="server" Text="">
                        <asp:LinkButton ID="LinkButton4" runat="server" CommandName="Page" CommandArgument="Last" CssClass="Linkbutton">Last
                    </pagertemplate>
                    <%--<added by="" naresh=""></added>--%>
                
            </td>
        </tr>
        <asp:Label ID="lblresult" runat="server" Text="">
        <asp:Literal runat="server" ID="Literal1" />
    </table>
    <br />
    <hr />
    <table class="style1">
        <tr>
            <td class="style2"> </td>
            <td class="style2"><asp:Label ID="lblstr" runat ="server" Text ="*" Font-Bold ="true" Font-Size ="Large" ForeColor ="Blue">
            </td>
            <td class="style3">
                     <label style ="font-weight:bold;font-family:Times New Roman;font-size:small;">Product Description</label></td>
            <td>
                     = This is Used for Single Phase Meter 
            </td>
        </tr>
        <tr>
            <td class="style2">
                 
                    </td>
            <td class="style2">
                <asp:Label ID="Label2" runat ="server" Text ="*" Font-Bold ="true" Font-Size ="Large" ForeColor ="Blue" >
            </td>
            <td class="style3">
                      <label style ="font-weight:bold;font-family:Times New Roman;font-size:small;">In Stock</label></td>
            <td>
                     = Total Stock in Godown/Store Room (Ex:10,000)</td>
        </tr>
        <tr>
            <td class="style2">
                 </td>
            <td class="style2">
                <asp:Label ID="Label3" runat ="server" Text ="*" Font-Bold ="true" Font-Size ="Large" ForeColor ="Blue">
            </td>
            <td class="style3">
                    <label style ="font-weight:bold;font-family:Times New Roman;font-size:small;">Commited</label></td>
            <td>
                     = How Much Stock U have Dispatched (Ex:500) //Once check In Stock Quantity B4 Committed)</td>
        </tr>
        <tr>
            <td class="style2">
                 </td>
            <td class="style2">
                <asp:Label ID="Label4" runat ="server" Text ="*" Font-Bold ="true" Font-Size ="Large" ForeColor ="Blue">
            </td>
            <td class="style3">
                     <label style ="font-weight:bold;font-family:Times New Roman;font-size:small;">On Order</label></td>
            <td>
                     = PO of Order By Supplier/Vendor (Ex:1000)</td>
        </tr>
        <tr>
            <td class="style2">
                 </td>
            <td class="style2">
                <asp:Label ID="Label5" runat ="server" Text ="*" Font-Bold ="true" Font-Size ="Large" ForeColor ="Blue">
            </td>
            <td class="style3">
                      <label style ="font-weight:bold;font-family:Times New Roman;font-size:small;">WholeSale</label></td>
            <td>
                     = Total Price Of  each  OnOrder Product (Ex: Rs 27000.00)</td>
        </tr>
    </table>
    
  <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 System.Xml;

public partial class ProductGrid : System.Web.UI.Page
{
    static string PN;
    //ds is used Store Data And Bind to Grid
    static DataSet ds;
    // con is used for sqlConnection it get the Connection from connectionString class
    SqlConnection con = new SqlConnection(IMS.ConnectionString.getValue());
   protected void Page_Load(object sender, EventArgs e)
    {
        sessions.getsessions();  //by Shruthi
        SqlDataAdapter daAuth = new SqlDataAdapter("select ListOfProducts from submenu where user_type_id='" + Session["UTI"].ToString() + "'", con);
        DataSet dsAuth = new DataSet();
        daAuth.Fill(dsAuth, "Submenu");
        if (dsAuth.Tables["Submenu"].Rows[0]["ListOfProducts"].ToString() == "False")
        {
            Response.Redirect("default.aspx");
        }
        btn_delProduct.Enabled=btn_addProductDetails.Enabled=btnUpdate.Enabled=btn_show_ProductDetails.Enabled= false;
       btn_addNewProduct.Enabled = true;
        //HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache);
        if (Page.IsPostBack == false)
        {
            getdata();
            IMSNiana.ProductName = "";
        }
              //}
    }

    
   public string getVal()
    {
        return PN;
    }
    public void getdata()
    {
        //da is fetch datafrom DataBase
        SqlDataAdapter da = new SqlDataAdapter("select * from product", con);
        ds = new DataSet();
        //it fill the dataset(ds)'s table with Product
        da.Fill(ds, "Product");
        //GVProduct.Dispose();
        GVProduct.DataSource = ds.Tables["Product"];
        GVProduct.DataBind();
    }

    public string getPName()
    {
        return IMSNiana.ProductName;
    }
    
    protected void GVProduct_RowCreated(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            e.Row.Attributes.Add("onmouseover", "this.originalstyle=this.style.backgroundColor;this.style.backgroundColor='orange'");
            e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor=this.originalstyle;");
        }
        if (e.Row.RowType == DataControlRowType.Pager)
        {
            GridViewRow gvr = e.Row;
            LinkButton lb = (LinkButton)gvr.Cells[0].FindControl("p0");
            lb.Command += new CommandEventHandler(lb_Command);
            lb = (LinkButton)gvr.Cells[0].FindControl("p1");
            lb.Command += new CommandEventHandler(lb_Command);
            lb = (LinkButton)gvr.Cells[0].FindControl("p2");
            lb.Command += new CommandEventHandler(lb_Command);
            lb = (LinkButton)gvr.Cells[0].FindControl("p4");
            lb.Command += new CommandEventHandler(lb_Command);
            lb = (LinkButton)gvr.Cells[0].FindControl("p5");
            lb.Command += new CommandEventHandler(lb_Command);
            lb = (LinkButton)gvr.Cells[0].FindControl("p6");
            lb.Command += new CommandEventHandler(lb_Command);
        }
    }
    protected void GVProduct_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            e.Row.Attributes.Add("onmouseover", "MouseEvents(this, event)");
            e.Row.Attributes.Add("onmouseout", "MouseEvents(this, event)");
                    
        }
    }
    protected void chkselect_CheckedChanged(object sender, EventArgs e)
    {
        foreach (GridViewRow gvr in GVProduct.Rows)
        {
            CheckBox chk = (CheckBox)gvr.FindControl("chkselect");
            if (chk.Checked == true)
            {
                btn_addProductDetails.Enabled = btn_delProduct.Enabled = btnUpdate.Enabled =  btn_show_ProductDetails.Enabled = true;
                btn_addNewProduct.Enabled = false;
        
                Label pn = (Label)gvr.FindControl("productname");
                IMSNiana.ProductName = pn.Text;
               
                break;
            }
            else
            {
                btn_addProductDetails.Enabled = btn_delProduct.Enabled = btnUpdate.Enabled =btn_show_ProductDetails.Enabled= false;
                btn_addNewProduct.Enabled = true;
            }
        }
    }
   
    protected void GVProduct_DataBound(object sender, EventArgs e)
    {
        try  
        {
            GridViewRow gvrow = GVProduct.BottomPagerRow;
            Label lblcurrentpage = (Label)gvrow.Cells[0].FindControl("CurrentPage");
            lblcurrentpage.Text = Convert.ToString(GVProduct.PageIndex + 1);
            int[] page = new int[7];
            page[0] = GVProduct.PageIndex - 2;
            page[1] = GVProduct.PageIndex - 1;
            page[2] = GVProduct.PageIndex;
            page[3] = GVProduct.PageIndex + 1;
            page[4] = GVProduct.PageIndex + 2;
            page[5] = GVProduct.PageIndex + 3;
            page[6] = GVProduct.PageIndex + 4;
            for (int i = 0; i < 7; i++)
            {
                if (i != 3)
                {
                    if (page[i] < 1 || page[i] > GVProduct.PageCount)
                    {
                        LinkButton lnkbtn = (LinkButton)gvrow.Cells[0].FindControl("p" + Convert.ToString(i));
                        lnkbtn.Visible = false;
                    }
                    else
                    {
                        LinkButton lnkbtn = (LinkButton)gvrow.Cells[0].FindControl("p" + Convert.ToString(i));
                        lnkbtn.Text = Convert.ToString(page[i]);
                        lnkbtn.CommandName = "PageNo";
                        lnkbtn.CommandArgument = lnkbtn.Text;

                    }
                }
            }
            if (GVProduct.PageIndex == 0)
            {
                LinkButton lnkbtn = (LinkButton)gvrow.Cells[0].FindControl("LinkButton1");
                lnkbtn.Visible = false;
                lnkbtn = (LinkButton)gvrow.Cells[0].FindControl("LinkButton2");
                lnkbtn.Visible = false;
            }
            if (GVProduct.PageIndex == GVProduct.PageCount - 1)
            {
                LinkButton lnkbtn = (LinkButton)gvrow.Cells[0].FindControl("LinkButton3");
                lnkbtn.Visible = false;
                lnkbtn = (LinkButton)gvrow.Cells[0].FindControl("LinkButton4");
                lnkbtn.Visible = false;
            }
            if (GVProduct.PageIndex > GVProduct.PageCount - 5)
            {
                Label lbmore = (Label)gvrow.Cells[0].FindControl("nmore");
                lbmore.Visible = false;
            }
            if (GVProduct.PageIndex < 4)
            {
                Label lbmore = (Label)gvrow.Cells[0].FindControl("pmore");
                lbmore.Visible = false;
            }
        }
        catch
        {
        }
}
  public  void lb_Command(object sender, CommandEventArgs e)
   {
       GVProduct.PageIndex = Convert.ToInt32(e.CommandArgument) - 1;
       getdata();
    }

  protected void GVProduct_PageIndexChanging1(object sender, GridViewPageEventArgs e)
  {
      GVProduct.PageIndex = e.NewPageIndex;
      getdata();
  }
  protected void GVProduct_SelectedIndexChanged(object sender, EventArgs e)
  {
  }
  protected void btn_delProduct_Click1(object sender, EventArgs e)
  {
      SqlDataAdapter da = new SqlDataAdapter("select product_id from Product where product_name='" + IMSNiana.ProductName + "'", con);
      //ds is used store data fetched from Database
      DataSet ds = new DataSet();
      da.Fill(ds, "PN");
      string PId = ds.Tables["PN"].Rows[0][0].ToString();
      da = new SqlDataAdapter(" delete from ProductDetails where product_id='" + PId + "' delete from  Product where product_id='" + PId + "'", con);
      ds = new DataSet();
      da.Fill(ds, "Product");
      getdata();
     
  }
}

</code>