/// <summary>
        /// Capture screenshot, saves it locally and add to upload manager stack
        /// saves the picture on date time format
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void OnCaptureClick(object sender, RoutedEventArgs e)
        {
            this.Hide();
            m_sFileName = m_ImageCaptureManager.CaptureScreen();
            ExportCanvasToFile();
            string fullFilePath = Path.Combine(GlobalContants.screenshotFolderPath, m_sFileName + ".jpeg");

            UploadManager.Instance.setCourseID(m_iCourseID);
            UploadManager.Instance.uploadFilesStack.Push(fullFilePath);
            //CursorButton_Click(sender,e);
            if (UploadManager.Instance.isThreadSleep)
            {
                m_FileUploadThread.Interrupt();
            }
            itemsControl.Items.Add(m_ImageCaptureManager.CreatePreviewThumbnail(fullFilePath));
            strokesItemsControl1.Items.Add(m_ImageCaptureManager.CreatePreviewStrokeThumbnail(fullFilePath));
        }