##
helpFrame.addPage()

    h.addPage(span,element, element,...)

creates a new page for helpFrame "h", and fills it with HTML text from "span". The "elements" are the DOM and MapClient objects that are shown when the page is selected. The "span" variable can be:

- A DOM variable pointing to a defined HTML element
- A string: the id of an already defined HTML element
- null, when the helpFrame only serves for navigation.

The two first methods are equivalent. The string is internally converted to a DOM variable by the "document.getElementById()" method. The element can be any HTML element, but I always make it a SPAN, with text internally formatted in subSPANs
Each "element" variable can be:

- A MapClient window, menu, slider or other helpFrame
- A DOM variable pointing to a defined HTML element
- A string: the id of an already defined HTML element
- An Array, containing any of the above

Elements can belong to multiple pages. To facilitate the management of complex applications, they can be grouped in arrays. All MapClient and HTML elements that are not explicitly assigned to a page are visible throughout the whole MapClient application.