DOM and XHTML/HTML

W3C XML DOM allows the all aspects of the document to be accessed and manipulated.

getElementById is a frequently seen method

Once we have the node selected, we can manipulate its properties. In this case, we are changing the "visibility" to "visible" or "hidden".

Showing and Hiding Menus, part 1

Showing and Hiding Menus, part 2

Block whose visibility is set can be positioned absolutely.