Creating a Menu from existing markup with items organized into groups

The markup for a Menu control follows that of YAHOO.widget.Module, with its body element (<div class="bd">) containing a list element (<ul>).

Each item in a Menu is represented by a list item element (<li class="yuimenuitem">), each of which has a label (<a class="yuimenuitemlabel">) that can contain plain text or HTML.

The body of a Menu instance can house many <ul> elements to organize related items into groups.

To instantiate a Menu based on existing HTML, pass the id of its corresponding HTML element (in this case "basicmenu") to the Menu constructor (YAHOO.widget.Menu) then call the render method with no arguments.