Custome Paging using Stored Procedure

[Kiresh]

I have problem with my development task.
My ASPX File

<telerik:RadGrid ID="grd1" runat="server" AllowFilteringByColumn="True"
              AllowPaging="True" AllowCustomPaging="true" AutoGenerateColumns="False" GridLines="None"
              OnItemDataBound="grd1_OnItemDataBound" OnItemCreated="grd1_ItemCreated"
              Width="100%" Skin="Windows7" ShowGroupPanel="false" CellSpacing="0" PageSize="50"
              OnNeedDataSource="grd1_NeedDataSource" OnPageIndexChanged="grd1_PageIndexChanged"
              OnPageSizeChanged="grd1_PageSizeChanged">

and my Code file is

protected void grd1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
{
        grd1.VirtualItemCount = 100000;
        grd1.DataSource = GetDataSource();
        grd1.DataBind();
}

private IEnumerable<SearchClass> Select(int pageSize, int pageIndex)
    {

      IQueryable<SearchClass> searchObj = DataClassLib.Search(pageSize, pageIndex).AsQueryable();

      try
      {
        searchObj = searchObj .Select(x => new SearchClass
        {
          Id = x.Id,
          Name = x.Name,
        });

      }
      catch (Exception ex)
      {
        throw ex;
      }

      return searchObj;
    }

 private IEnumerable<SearchClass> GetDataSource()
    {
      int pageIndex = grd1.CurrentPageIndex;
      int pageSize = grd1.PageSize;

      if (pageIndex == 0)
        pageIndex = 1;
      IEnumerable<SearchClass> data = Select(pageSize,pageIndex);
      return data == null ? new List<SearchClass>() : data.Skip(pageSize * pageIndex).Take(pageSize);
    }

i used Telerik RadGrid and i need to show pagination using Stored Procedure  where procedure returns only 50 records from database though there are 100K records in table.

Paging showing correctly.
using this code i get 50 records from database but does not appear in  grid , i debug my code and its shows me  in GetDataSource() that returns 50 records but when debug point comes to grd1.DataSource = GetDataSource(); this line in datasource it show me 0 count.

can anybody guess why this happening

Thanks