You can integrate Smartling's Context Capture Extension with custom JavaScript. This should be applied before taking a snapshot of the page. Integrating custom JavaScript is especially useful, for example, to show or hide certain elements on a page or to manipulate markup so that it will match strings in files.
In Chrome, right-click the Chrome Extension icon and select Options
Check Execute JavaScript prior to snapshot and enter the code you wish to execute.
Changes are automatically saved
Alternatively, you can customize Visual Context for your entire Smartling Project by inserting CSS and/or JavaScript in your Smartling Project settings.