ASP.NET 2.0

ex.Message: Cannot access a closed file.
e.StackTrace:
   at System.IO.__Error.FileNotOpen()
   at System.IO.FileStream.Seek(Int64 offset, SeekOrigin origin)
   at System.Web.HttpRawUploadedContent.TempFile.GetBytes(Int32 offset, Int32 length, Byte[] buffer, Int32  bufferOffset)
   at System.Web.HttpRawUploadedContent.WriteBytes(Int32 offset, Int32 length, Stream stream)
   at System.Web.HttpInputStream.WriteTo(Stream s)
   at System.Web.HttpPostedFile.SaveAs(String filename)
   at korthuset_net.aspSmartUpload1.uploadLogics(String dirPath, HttpPostedFile sourceFile, HttpPostedFile thumbFile) in d:\\Projects\\KorthusetWeb-TESTING\\aspSmartUpload1.aspx.cs:line 236"

protected override void Page_Load(object sender, System.EventArgs e)
{
	base.Page_Load (sender, e);
			
	//Get total number of uploaded files
	int intFileCount = Int32.Parse(Request.Form["FileCount"]);

	string strGalleryPath = @"C:\\Gallery"
	if(!Directory.Exists(strGalleryPath ))
		Directory.CreateDirectory(strGalleryPath );
	if(!Directory.Exists(strGalleryPath + "\\Thumbnails"))
		Directory.CreateDirectory(strGalleryPath + "\\Thumbnails");


	dirPath = strGalleryPath +"\\";

	//We iterate through the uploaded files and save them and appropriate data
	for (int i = 1; i <= intFileCount; i++)
	{
	   //Get source image and save it to disk
                sourceFile = Request.Files["SourceFile_1"];
                thumbFile = Request.Files["Thumbnail1_1"];

                tr = new Thread(new ThreadStart(this.NewThread));
                tr.Start();
             }
}

private void NewThread()
{
            try
            {
                uploadLogics(dirPath, sourceFile, thumbFile);
            }
            catch (Exception ex)
            {
                string exp = ex.Message;
            }
            finally
            {
                tr.Abort();
            }

        }

        private void uploadLogics(string dirPath, HttpPostedFile sourceFile, HttpPostedFile thumbFile)
        {
            string fileName;
            string ext;
            long size;

            //get file name
            fileName = Path.GetFileName(sourceFile.FileName);

            ext = fileName.Substring(fileName.LastIndexOf("."));
            fileName = fileName.Substring(0, fileName.LastIndexOf("."));

            //if file is tif it will be saved as .jpg
            bool tif = false;
            if (ext.ToLower().Equals(".tif") || ext.ToLower().Equals(".tiff"))
            {
                ext = ".jpg";
                tif = true;
            }

            fileName = Regex.Replace(fileName, @"[ ',;+%]", "_");

            //if already was uploaded file with that name, the current file
            string newFileName = fileName + ext;
            int j = 1;
            while (File.Exists(dirPath + newFileName))
            {
                newFileName = j + "_" + fileName + ext;
                j++;
            }
            ext = newFileName.Substring(newFileName.LastIndexOf("."));
            fileName = newFileName.Substring(0, newFileName.LastIndexOf("."));

            //shrink the file name to max 50 characters
            fileName = fileName.Length > 50 ? fileName.Substring(0, 50) : fileName;

            //save file 
            try
            {
                if (tif)
                {
                    ext = ".jpg";

                    System.Drawing.Image im = System.Drawing.Image.FromStream(sourceFile.InputStream);
                    im.Save(dirPath + fileName + ".jpg", ImageFormat.Jpeg);
                    im.Dispose();
                }
                else
                {
                    sourceFile.SaveAs(dirPath + fileName + ext);
                }
                size = sourceFile.InputStream.Length;
                //Get first thumbnail (the single thumbnail in this code sample)
                thumbFile.SaveAs(dirPath + "Thumbnails\\" + fileName + ext);

                //database insert code.....
            }
            catch (Exception ex)
            {
                 string message = ex.Message;
                 string stack = ex.StackTrace;
            }
}

var iu = new ImageUploaderWriter("ImageUploader", 650, 350);
iu.activeXControlEnabled = true;
iu.javaAppletEnabled = true;
iu.activeXControlCodeBase = "ImageUploader4.cab";
iu.javaAppletCodeBase="./";

iu.addParam("PaneLayout", "TwoPanes");
iu.addParam("BackgroundColor", "#ffffff");
iu.addParam("UploadThumbnail1FitMode", "Fit");
iu.addParam("UploadThumbnail1Width", "120");
iu.addParam("UploadThumbnail1Height", "120");
iu.addParam("UploadThumbnail1JpegQuality", "60");
iu.addParam("FilesPerOnePackageCount", "1");
iu.addParam("AutoRecoverMaxTriesCount", "5");
iu.addParam("AutoRecoverTimeOut", "1200");
iu.addParam("ShowDebugWindow", "True");
iu.addParam("AdditionalFormName", "Form1");
iu.addParam("AllowRotate", "False");
iu.addParam("Action", "aspSmartUpload1.aspx");
iu.addParam("FileMask", "*.jpg;*.bmp;*.tiff;*.tif");
iu.addParam("MaxFileSize", "5242880");
iu.addParam("ButtonStopText", "<%=languageText["bStop"]%>");
iu.addParam("ShowDescriptions", "0");
iu.addParam("CheckFilesBySelectAllButton", "True");
iu.addEventListener("Progress", "ImageUploaderID_Progress");

iu.writeHtml();
		
function ImageUploaderID_Progress(Status, Progress, ValueMax, Value, StatusText)
{
	if (Status=="COMPLETE")
	{
		tt = window.setTimeout("doAction()",2000);
	}
	if (Status=="CANCEL")
	{
		tt = window.setTimeout("doAction()",2000);
	}
}