Download File From NAS using Web Applocation

protected void DownloadFile()
{
    try
    {
        string strURL = \\bac\SDF\ASD.XML;
        WebClient req = new WebClient();
        HttpResponse response = HttpContext.Current.Response;
        response.Clear();
        response.ClearContent();
        response.ClearHeaders();
        response.Buffer = true;
        response.AddHeader("Content-Disposition", "attachment;filename=\"" + strURL + "\"");
        byte[] data = req.DownloadData(strURL);
        Response.ContentType = "application/UnknownType";
        Response.ContentEncoding = Encoding.Unicode;
        response.BinaryWrite(data);
        response.End();
    }
    catch (Exception ex)
    {
        ex.Data.ToString();
    }
}