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 Telerik.Web.UI;
using System.Collections.Specialized;
using System.Collections;
using System.Data.OleDb;

public partial class Default2 : System.Web.UI.Page
{

    protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
    {
        RadGrid1.DataSource = new string[] { "1", "2", "3" };
    }
    protected void RadGrid1_ItemCreated(object sender, GridItemEventArgs e)
    {
        if (e.Item is GridEditableItem && e.Item.IsInEditMode)
        {
            Label lbl = new Label();
            lbl.ID = "Lbl1";
            lbl.Text = "some text";
            (e.Item as GridEditableItem).Cells[1].Controls[0].Controls.AddAt(0, lbl);
        }
    }
}