protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (txtloginUser.Value.ToString().Trim() != string.Empty && txtloginPw.Value.ToString().Trim() != string.Empty)
        {
            CheckLoginValidity();
        }
    }

    protected void CheckLoginValidity()
    {
        try
        {
            
                // Read XML File for Checking userName and Password
                DataSet ds = new DataSet();
                ds.ReadXml(Server.MapPath("sample.xml"));
                Boolean IsValid = false;

                foreach (DataRow dr in ds.Tables[0].Rows)
                {
                    if (!IsValid)
                    {
                        if (txtloginUser.Value.ToString().Trim() == dr["name"].ToString() && txtloginPw.Value.ToString().Trim() == dr["pass"].ToString())
                        {
                            Session["Authentication"] = "Admin";
                            Session["Permission"] = dr["permission"].ToString();
                            string URL = dr["permission"].ToString();
                            IsValid = true;
                            //Response.Redirect(URL,false);
                            
                        }
                    }
                }

                if (!IsValid)
                {
                    Session["ErrorMessage"] = "Username and password do not match";
                    Response.Redirect(Request.ApplicationPath + "//ErrorPage.aspx", false);
                }
                else
                {
                    Response.Redirect("UserNames.aspx", false);
                }


        }
        catch (Exception ex)
        {
            Session["ErrorMessage"] = ex.Message.ToString();
            Response.Redirect(Request.ApplicationPath + "//ErrorPage.aspx");

        }
        finally
        {        
        

        }

    }

public void LoadXML()
    {
        DataSet objdata = new DataSet();

        try
        {
            objdata.ReadXml(Server.MapPath("sample.xml"));
            strCount = objdata.Tables[0].Rows.Count.ToString();  
            datagrid1.DataSource  = objdata;
            datagrid1.DataBind();

               
           
        }

        catch
        {

            CreateXML();
        }

    }


    public void CreateXML()
    {
        DataSet objdata = new DataSet("root");
        DataTable dt = new DataTable("record");
        DataRow dr = default(DataRow);

        dt.Columns.Add(new DataColumn("aid"));
        dt.Columns.Add(new DataColumn("name"));
        dt.Columns.Add(new DataColumn("pass"));
        dt.Columns.Add(new DataColumn("permission"));

        dr = dt.NewRow();
        dr[0] = "1";
        dr[1] = "No Data";
        dr[2] = "No Data";
        dr[3] = "No Data";

        dt.Rows.Add(dr);

        objdata.Tables.Add(dt);

        datagrid1.DataSource  = objdata;
        datagrid1.DataBind(); 

        objdata.WriteXml(Server.MapPath("sample.xml"));

        LoadXML();
    }


    public void setEditMode(object Sender, DataGridCommandEventArgs e)
    {

        DataSet objdata = new DataSet();
        string x1;
          


        objdata.ReadXml(Server.MapPath("sample.xml"));       

        x1  = (string)datagrid1.DataKeys[e.Item.ItemIndex].ToString() ;

        objdata.Tables["record"].DefaultView.RowFilter = "aid='" + x1 + "'";

        if (objdata.Tables["record"].DefaultView.Count > 0)
        {
            error4.Visible = false;
            datagrid1.EditItemIndex = e.Item.ItemIndex;
            datagrid1.ShowFooter = false;
            LoadXML();
        }
        else
        {
            error4.Visible = true;
        }
    }


    public void cancelEdit(object sender, DataGridCommandEventArgs E)
    {
        datagrid1.EditItemIndex = -1;
        datagrid1.ShowFooter = true;
        error1.Visible =  false ;
        error2.Visible = false;
        error3.Visible = false;
        error4.Visible = false;
        error5.Visible = false;

        LoadXML();

    }


    public void DelXML(object S, DataGridCommandEventArgs e)
    {
        if (e.CommandName == "Delete")
        {
            if (datagrid1.EditItemIndex == -1)
            {
                error5.Visible = false;
                string x1 = null;

                x1 = datagrid1.DataKeys[e.Item.ItemIndex].ToString() ;

                DataSet objdata = new DataSet();
                try
                {
                    objdata.ReadXml(Server.MapPath("sample.xml"));
                    objdata.Tables["record"].DefaultView.RowFilter = "aid='" + x1 + "'";
                    if (objdata.Tables["record"].DefaultView.Count > 0)
                    {
                        objdata.Tables["record"].DefaultView.Delete(0);
                    }

                    objdata.Tables["record"].DefaultView.RowFilter = "";

                    objdata.WriteXml(Server.MapPath("sample.xml"));
                }
                catch
                {
                    CreateXML();
                }

                LoadXML();
            }
            else
            {
                error5.Visible = true;
            }
        }
    }


    public void UpdateXML(object s, DataGridCommandEventArgs e)
    {
        if (e.CommandName == "Update")
        {
            string str1 = null;
            string str2 = null;
            string str3 = null;
            int v1;
            TextBox txt1 = new TextBox();
            TextBox txt2 = new TextBox();
            TextBox txt3 = new TextBox();
           
            DataSet objdata = new DataSet();
            string x1 = null;

            objdata.ReadXml(Server.MapPath("sample.xml"));

            v1 = (int) e.Item.ItemIndex;

            x1 = datagrid1.DataKeys[e.Item.ItemIndex].ToString() ;

            objdata.Tables["record"].DefaultView.RowFilter = "aid='" + x1 + "'";

            if (objdata.Tables["record"].DefaultView.Count > 0)
            {
                error3.Visible = false;

                txt1 = (TextBox )e.Item.FindControl("name_edit");
                txt2 = (TextBox)e.Item.FindControl("pass_edit");
                txt3 = (TextBox)e.Item.FindControl("permission_edit");

                objdata.Tables["record"].Rows[v1]["name"] = txt1.Text;
                objdata.Tables["record"].Rows[v1]["pass"] = txt2.Text;
                objdata.Tables["record"].Rows[v1]["permission"] = txt3.Text;
                datagrid1.DataSource  = objdata;
                datagrid1.DataBind(); 

                objdata.WriteXml(Server.MapPath("sample.xml"));

                datagrid1.EditItemIndex = -1;
                LoadXML();
                datagrid1.ShowFooter = true;
            }
            else
            {
                error3.Visible = true;
            }
        }
    }


    public void doInsert(object s, DataGridCommandEventArgs e)
    {

        if (e.CommandName == "doAdd")
        {
            string v1 = null;
            TextBox tadd1 = new TextBox();
            TextBox tadd2= new TextBox();
            TextBox tadd3= new TextBox();
            TextBox tadd4 = new TextBox();

            DataSet objdata = new DataSet();
            DataRow dr = default(DataRow);

            objdata.ReadXml(Server.MapPath("sample.xml"));

            tadd1 = (TextBox)e.Item.FindControl("aid_add");
            tadd2 = (TextBox)e.Item.FindControl("name_add");
            tadd3 = (TextBox)e.Item.FindControl("pass_add");
            tadd4 = (TextBox)e.Item.FindControl("permission_add");

            try
            {
                
                error2.Visible = false;

                if (Convert.ToInt32(tadd1.Text)  < 1)
                {
                    tadd1.Text = "";
                    error2.Visible = true;
                }
            }
            catch
            {
                tadd1.Text = "";
                error2.Visible = true;
            }

            if (!string.IsNullOrEmpty(tadd1.Text) & !string.IsNullOrEmpty(tadd2.Text) & !string.IsNullOrEmpty(tadd3.Text) & !string.IsNullOrEmpty(tadd4.Text))
            {
                objdata.Tables["record"].DefaultView.RowFilter = "aid='" + tadd1.Text + "'";
                if (objdata.Tables["record"].DefaultView.Count <= 0)
                {
                    error1.Visible = false;
                    objdata.Tables["record"].DefaultView.RowFilter = "";
                    dr = objdata.Tables["record"].NewRow();

                    dr[0] = tadd1.Text;
                    dr[1] = tadd2.Text;
                    dr[2] = tadd3.Text;
                    dr[3] = tadd4.Text;
                    objdata.Tables["record"].Rows.Add(dr);

                    objdata.WriteXml(Server.MapPath("sample.xml"));
                    LoadXML();
                }
                else
                {
                    error1.Visible = true;
                    error1.Text = "Id must be unique";
                }
            }
        }
    }


   
    protected int showval1()
    {
        int coun = Convert.ToInt32(strCount) + 1;
        
        return coun;
    }