Stuart Colville investigates the differences between form.getAttribute('action') and form.action, also the cross-browser differences, when the action is a relative URL. One way returns a relative URL, and the other returns a fully qualified URL.
Another Douglas Crockford video. This time Douglas talks about the Document Object Model, about how Java failed, and JavaScript evolved thanks to DHTML and DOM. He talks about how to use DOM to traversing and manipulating elements in an HTML document, walking the DOM, making elements, innerHTML, as well as Events, memory leaks. He talks about the cracks in DOM, and how we must be prepared to back off when we hit the browser limits of DOM.