Help....Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in...

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Security;
using System.Data.SqlClient;

namespace Ordering_System.member
{
    public partial class MemEditDetails : System.Web.UI.Page
    {
        UserDBDataContext db = new UserDBDataContext();
        string cs = Global.CS;

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                bool found = false;

                string id = User.Identity.Name;

                string sql = "SELECT Username FROM Member WHERE Username = @Id";
                SqlConnection con = new SqlConnection(cs);
                SqlCommand cmd = new SqlCommand(sql, con);
                cmd.Parameters.AddWithValue("@Id", id);

                con.Open();
                SqlDataReader dr = cmd.ExecuteReader();

                if (dr.Read())
                {
                    found = true;
                    lblMem.Text = (string)dr["Username"];
                    txtFname.Text = (string)dr["MemFname"]; <----Happened here  

                                                           System.IndexOutOfRangeException

                    txtLname.Text = (string)dr["MemLname"];
                    txtMYKAD.Text = (string)dr["MemIC"];
                    txtDate.Text = (string)dr["MemDOB"];
                    rblGender.Text = (string)dr["Gender"];
                    txtAddress.Text = (string)dr["MemAddress"];
                    txtPostCode.Text = (string)dr["Postcode"];
                    ddlstate.Text = (string)dr["State"];
                    txtContact.Text = (string)dr["MemContact"];
                    txtEmail.Text = (string)dr["MemEmail"];


                }
                dr.Close();
                con.Close();

                if (!found)
                {
                    Response.Redirect("Home.aspx");
                }

            }
        }

        protected void btn_Edit_Click(object sender, EventArgs e)
        {
            if (Page.IsValid)
            {
                string id = lblMem.Text;
                string Fname = txtFname.Text;    
                string Lname = txtLname.Text;
                string ic = txtMYKAD.Text;
                string dob = txtDate.Text;
                string gender = rblGender.Text;
                string address = txtAddress.Text;
                string postcode = txtPostCode.Text;
                string state = ddlstate.Text;
                string contact = txtContact.Text;
                string email = txtEmail.Text;
                string oldPW = oldPass.Text;
                string newPW = newPass.Text;
                string confirmPW = confirmPass.Text;

                User u = db.Users.SingleOrDefault(
                           x => x.Username == id &&
                                x.Hash == Security.GetHash(oldPW)
                                );


                if (u != null)
                {

                    if (newPass.Text == confirmPass.Text)
                    {
                        string sql = @"UPDATE Member SET Hash = @Password MemFname = @Fname,MemLanme = @Lname MemIC = @Ic, MemDOB = @DOB, Gender = @Gender , 
                            MemAddress = @Address, Postcode = @Postcode,  State = @State, MemContact = @Contact,
                            MemEmail = @Email WHERE Username = @Id";
                        SqlConnection con = new SqlConnection(cs);
                        SqlCommand cmd = new SqlCommand(sql, con);
                        cmd.Parameters.AddWithValue("@Password", Security.GetHash(newPW));
                        cmd.Parameters.AddWithValue("@Id", id);
                        cmd.Parameters.AddWithValue("@Fname", Fname);
                        cmd.Parameters.AddWithValue("@Lname", Lname);
                        cmd.Parameters.AddWithValue("@Ic", ic);
                        cmd.Parameters.AddWithValue("@DOB", dob);
                        cmd.Parameters.AddWithValue("@Gender", gender);
                        cmd.Parameters.AddWithValue("@Address", address);
                        cmd.Parameters.AddWithValue("@Postcode", postcode);
                        cmd.Parameters.AddWithValue("@State", state);
                        cmd.Parameters.AddWithValue("@Contact", contact);
                        cmd.Parameters.AddWithValue("@Email", email);

                        con.Open();
                        cmd.ExecuteNonQuery();
                        con.Close();

                        Response.Redirect("Home.aspx");

                    }
                    else
                    {
                        CustomValidator2.IsValid = false;
                    }

                }
                else
                {
                    CustomValidator1.IsValid = false;

                }
            }
        }
    }
}