ASP.NET

private void subDisplayReport(ReportClass rptObject, DataSet lDataSet) 
{ 
    rptObject.SetDataSource(lDataSet); 
    rptObject.ExportOptions.FormatOptions = new ExcelFormatOptions(); 
    rptObject.ExportOptions.ExportFormatType = ExportFormatType.Excel; 
    ExportRequestContext req = new ExportRequestContext(); 
    req.ExportInfo = rptObject.ExportOptions; 
    System.IO.Stream st; 
    st = rptObject.FormatEngine.ExportToStream(req); 
    byte[] b = new byte[(int)st.Length + 1]; 
    st.Read(b, 0, (int)st.Length); 
    Response.ClearContent(); 
    Response.ClearHeaders(); 
    Response.ContentType = "application/xls"; 
    Response.AddHeader("content-disposition", "inline; filename=MyReport.xls"); 
    Response.BinaryWrite(b); 
    Response.End(); 
} 

document.getElementById("DropDownList")[document.getElementById("DropDownList").selectedIndex].value

Public Shared Function GetFormattedDate(ByVal strDate As String, _
 Optional ByVal InputFormat As char = "d") As Date
   Dim dtFormat As New DateTimeFormatInfo
   If InputFormat = "d" Then
     dtFormat.ShortDatePattern = "dd/MM/yyyy"
   Else
     dtFormat.ShortDatePattern = "MM/dd/yyyy"
   End If
   Return Date.Parse(strDate, dtFormat)
End Function