I solved my problem with dev express. by using this code:
<dx:ASPxFileManager ID="ASPxFileManager1" runat="server" Width="827px">
<Settings ThumbnailFolder="~\content\thumb\" />
<SettingsToolbar ShowDownloadButton="True" />
<SettingsEditing AllowDelete="True" AllowRename="True" />
<SettingsUpload Enabled="False">
</SettingsUpload>
</dx:ASPxFileManager>
<div id="upload-div">
<asp:FileUpload ID="Uploadaudio" runat="server" AllowMultiple="true" Width="200px"/>
</div>
<div id="upload-submit">
<asp:Button runat="server" ID="uploadedFile" Text="Upload" OnClick="uploadFile_Click" />
</div>
protected void uploadFile_Click(object sender, EventArgs e)
{
if (Uploadaudio.HasFiles)
{
foreach (HttpPostedFile uploadedFile in Uploadaudio.PostedFiles)
{
uploadedFile.SaveAs(System.IO.Path.Combine(Server.MapPath("~/content/uploads/bkfiles/" + BookId.ToString(CultureInfo.InvariantCulture) + "/"),
uploadedFile.FileName));
}
}
}