Ok, I am trying to figure out how to ajax the groupby functionality of the webgrid.  I tried the following... what am I missing?

using System;
using System.Data;
using System.Configuration;
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 Infragistics.WebUI.UltraWebGrid;
using LCF.BOL;


using System.Web.SessionState;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            AddUpcomingCareerFairs();
        }
    }

    public void AddUpcomingCareerFairs()
    {
        this.WebGridUpcoming.DataSource = UpcomingCareerFairs.GetUpcomingCareerFairs();
        this.WebGridUpcoming.DataBind();
    }

    protected void WebGridUpcoming_InitializeLayout(object sender, Infragistics.WebUI.UltraWebGrid.LayoutEventArgs e)
    {
        // Properties needed to enable LoadOnDemand
       
        WebGridUpcoming.Browser = BrowserLevel.Xml;
        e.Layout.LoadOnDemand = LoadOnDemand.Xml;

        // LoadOnDemand configuration options
        e.Layout.RowsRange = 20;
        e.Layout.XmlLoadOnDemandType = XmlLoadOnDemandType.Accumulative;

       
    }





    protected void WebGridUpcoming_InitializeDataSource(object sender, Infragistics.WebUI.UltraWebGrid.UltraGridEventArgs e)
    {
        this.AddUpcomingCareerFairs();
    }

  


}