Most WebKitX API methods require passing the CSS3 Selector of an HTML5 Element. While most web developers are familiar with the concept, it turns out that in some complex HTML layouts it gets hard to derive the CSS3 selector, especially when using FORM elements. To properly find the CSS3 selector you can use Chromium DevTools with WebKitX.ShowDevTools command and in the Elements Tab of Developer Tools, right-click the highlighted element and select Copy > Copy selector.