Encoding problem.

Hi every body, I am using such code to export to excel data, from DataList

Response.Clear();
Response.AddHeader("content-disposition", "attachment;filename=StandartReport.xls");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Charset = Encoding.Unicode.EncodingName;
Response.ContentType = "application/StandartReport.xls";

StringWriter stringWrite = new StringWriter();
System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
ReportList.RenderControl(htmlWrite);
Response.Write(stringWrite.ToString());
Response.End();
  As result I have in excel sheet incorrect Latvian character, I tried to use UTF-8, ...