export datatable to excel sheet

SqlConnection con = new SqlConnection();
        con.ConnectionString = ConfigurationManager.ConnectionStrings["cn"].ConnectionString;
        SqlDataAdapter adp = new SqlDataAdapter("select * from admins", con);
        DataSet ds = new DataSet();
        adp.Fill(ds);
        DataTable dt = ds.Tables[0];
        string attachment = "attachment; filename=Employee.xls";
        Response.ClearContent();
        Response.AddHeader("content-disposition", attachment);
        Response.ContentType = "application/vnd.ms-excel";
        string tab = "";
        foreach (DataColumn dc in dt.Columns)
        {
            Response.Write(tab + dc.ColumnName);
            tab = "\t";
        }
        Response.Write("\n"); 
        int i;
        foreach (DataRow dr in dt.Rows)
        {
            tab = "";
            for (i = 0; i < dt.Columns.Count; i++)
            {
                Response.Write(tab + dr[i].ToString());
                tab = "\t";
            }
            Response.Write("\n");
        }
        Response.End();