Adding CustomDataSet Lookup in AXGridview in EP in AX 2012

<asp:TemplateField ConvertEmptyStringToNull="False" HeaderText="Recruiter"
          SortExpression="Recruiter">
        <EditItemTemplate>
          <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("custRecruiter") %>'> >
          </asp:TextBox>
            <dynamics:AxLookup ID="AxLookup1" runat="server"  TargetControlId="TextBox1"
            onlookup="WorkOrdersLookup_Lookup" RunLookupDataSetWhenOkClicked="True"
             AutoPostBack="False">
            </dynamics:AxLookup>
         </EditItemTemplate>
         <ItemTemplate>
         <asp:Label ID="Label1" runat="server" Text='<%# Bind("custRecruiter") %>'>>
         </asp:Label>
         </ItemTemplate>
 </asp:TemplateField>


using Microsoft.Dynamics.Framework.BusinessConnector.Session;
using Proxy = Microsoft.Dynamics.Framework.BusinessConnector.Proxy;
using Microsoft.Dynamics.AX.Framework.Services.Client;
using Microsoft.Dynamics.AX.Framework.Portal.Data;

   private ISession AxSession
    {
        get
        {
            AxBaseWebPart webpart = AxBaseWebPart.GetWebpart(this);
            return webpart == null ? null : webpart.Session;
        }
    }


    protected void WorkOrdersLookup_Lookup(object sender, AxLookupEventArgs e)
    {

    AxLookup lookup = (AxLookup)sender;

    // Create the lookup data set. The DirParty table will be used.
    Proxy.SysDataSetBuilder sysDataSetBuilder;
    sysDataSetBuilder = Proxy.SysDataSetBuilder.constructLookupDataSet(AxSession.AxaptaAdapter, TableMetadata.TableNum(AxSession, "DirPartyTable"));

    // Set the generated data set as the lookup data set.
    lookup.LookupDataSet = new DataSet(AxSession, sysDataSetBuilder.toDataSet());

    //filter the lookup

    using (Proxy.Query query = lookup.LookupDataSet.DataSetViews[0].MasterDataSource.query())
    {
        // If the partyName is blank we assign the "*" as the range
        query.dataSourceNo(1).addRange(TableDataFieldMetadata.FieldNum(this.AxSession, "DirPartyTable", "Name")).value = "Ajay";
    }
       
  
    // Specify the fields for the lookup.
 
    lookup.Fields.Add(AxBoundFieldFactory.Create(AxSession, lookup.LookupDataSetViewMetadata.ViewFields["Name"]));
   
  
    // Specify the select field for the lookup.
    lookup.SelectField = "Name";

    }