An interface used by in-process accessibility clients
 to get style, window, markup and other information about
 a DOM node. When accessibility is active in Gecko,
 every DOM node can have one nsIAccessNode for each
 pres shell the DOM node is rendered in.
 The nsIAccessNode implementations are instantiated lazily.
 The nsIAccessNode tree for a given dom window
 has a one to one relationship to the DOM tree.
 If the DOM node for this access node is "accessible",
 then a QueryInterface to nsIAccessible will succeed.

[scriptable, uuid(46820f9b-3088-4046-ab0f-56fdacdc7a82)]
interface nsIAccessNode : nsISupports


 The DOM node this nsIAccessNode is associated with.
readonly attribute nsIDOMNode DOMNode
 The nsIAccessibleDocument that this nsIAccessNode
 resides in.
readonly attribute nsIAccessibleDocument accessibleDocument
 The first nsIAccessNode child
readonly attribute nsIAccessNode firstChildNode
 The innerHTML for the DOM node
 This is a text string of all the markup inside the DOM
 node, not including the start and end tag for the node.
readonly attribute DOMString innerHTML
 The last nsIAccessNode child
readonly attribute nsIAccessNode lastChildNode
 The next nsIAccessNode sibling
readonly attribute nsIAccessNode nextSiblingNode
 The number of DOM children for the DOM node, which
 matches the number of nsIAccessNode children for this
readonly attribute long numChildren
 The OS window handle for the window this node
 is being displayed in.
[noscript] readonly attribute voidPtr ownerWindow
 The parent nsIAccessNode
readonly attribute nsIAccessNode parentNode
 The previous nsIAccessNode sibling
readonly attribute nsIAccessNode previousSiblingNode
 A unique ID calculated for this DOM node, for the 
 purposes of caching and referencing this object.
[noscript] readonly attribute voidPtr uniqueID


 Get the nth child of this node
 @param childNum Zero-based child index
 @return The nth nsIAccessNode child
nsIAccessNode getChildNodeAt(in long childNum)
 Retrieve the computed style value for this DOM node, if it is a DOM element.
 Note: the meanings of width, height and other size measurements depend
 on the version of CSS being used. Therefore, for bounds information, 
 it is better to use nsIAccessible::accGetBounds.
 @param pseudoElt The pseudo element to retrieve style for, or NULL
                  for general computed style information for this node.
 @param propertyName Retrieve the computed style value for this property name,
                     for example "border-bottom".
DOMString getComputedStyleValue(in DOMString pseudoElt, in DOMString propertyName)