HTMLOptionsCollection Methods: add()
Inserts the element before the second argument. The second argument is just an element in the
before argument can be the index number of the element to be inserted before or the element's name. If the
before element is omitted,
null, or a number out of range, then the element will be added at the end of the
HTMLCollection. This method will throw a
HierarchyRequestError exception if element is an ancestor of the element into which it is to be inserted.