data not fetched when clicking on master or delete text....

<asp:hyperlinkfield datanavigateurlfields="Ecode,EmployeeName,Designation,Location" 
                         datanavigateurlformatstring="Delete.aspx?ECODE={0}&
                         ENAME={1}&DESIGNATION={2}&LOCATION={3}" 
                         text="DELETE" xmlns:asp="#unknown" />
<asp:templatefield headertext="ECODE" xmlns:asp="#unknown">
    <itemtemplate>
        <asp:label id="lblcode" runat="server" text="<%# Eval(" ecode=") %>"></asp:label>
    </itemtemplate>          
</asp:templatefield>

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using MehtaGroup.TelephoneDirectoryApp.Library;


public partial class EmpFetch : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void submit_Click(object sender, EventArgs e)
    {
        Library lib = new Library();
        string sEmp_name = empname.Text;
        DataTable dtEmpDetail = new DataTable();
        dtEmpDetail = lib.GetEmpInfo(sEmp_name);
        if (dtEmpDetail.Rows.Count > 0)
        {
            grdJobHistory.DataSource = dtEmpDetail;
            grdJobHistory.DataBind();
        }


    }
    protected void grdJobHistory_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {


    }

}