C# - Dynamically Change The Flajaxian Upload Folder Name?

I am trying to dynamically change the upload folder name, but it's not working form me.

I am using the Flajaxian S3 Amazon uploader. The code as follows

<fjx:FileUploader ID="FileUploader1" runat="server">
<Adapters>
<fjx:DirectAmazonUploader OnFileNameDetermining="FileUploader1_FileNameDetermining"
AccessKey="WebConfig:AmazonAccessKey"
SecretKey="WebConfig:AmazonSecretKey"
BucketName="media.sitename.com" />
</Adapters>
</fjx:FileUploader>

Server side code as follows

protected void Page_Load(object sender, EventArgs e)
{
((com.flajaxian.DirectAmazonUploader)FileUploader1.Adapters[0]).Path = Request.Params["sid"].ToString();

[code]....