private static void replaceTextBoxWithText(FlowDocument document, QuestionContent content, ContentPartCreated contentPartCreated)
        {
            List <InlineUIContainer> tempList = new List <InlineUIContainer>();

            foreach (var block in document.Blocks)
            {
                if (block is Paragraph)
                {
                    Paragraph para = block as Paragraph;
                    foreach (var inline in para.Inlines)
                    {
                        if (inline is InlineUIContainer)
                        {
                            tempList.Add(inline as InlineUIContainer);
                        }
                    }
                }
            }

            foreach (var inlineUIContainer in tempList)
            {
                if (inlineUIContainer.Child is Image) // replace image url with local url.
                {
                    Image image = inlineUIContainer.Child as Image;

                    Image newImage = new Image();

                    Uri         newUri = new Uri(CommonControlCreator.getImageFile(image.Tag as string, content));
                    BitmapImage newBi  = new BitmapImage(newUri);
                    newImage.Source         = newBi;
                    newImage.Width          = (1.0 == newBi.Width ? 50 : newBi.Width);
                    newImage.Height         = (1.0 == newBi.Height ? 50 : newBi.Height);
                    newImage.Tag            = image.Tag;
                    inlineUIContainer.Child = newImage;
                }
                else if (inlineUIContainer.Child is TextBox) // replace textbox with richtextbox
                {
                    TextBox textBox = inlineUIContainer.Child as TextBox;

                    TextBlock richTextBox = new TextBlock();
                    richTextBox.Text        = "(                )";
                    richTextBox.Tag         = textBox.Tag;
                    inlineUIContainer.Child = richTextBox;
                    if (contentPartCreated != null)
                    {
                        contentPartCreated(richTextBox);
                    }
                }
            }
        }