how to export dataset in excel using c#

 DataTable dt = new DataTable();
DataTable dt1 = new DataTable();
DataTable dt2 = new DataTable();

dt = ds.Tables[0];
dt1 = ds.Tables[1];
dt2 = ds.Tables2];
//for first file
        string attachment = "attachment; filename=file1.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");
        }
// write same code for second and third file with dt1 and dt2 data tables
 Response.End();