Request: A feature for swapping the Z index of two elements.
Type of function: Prototype
function name: .zSwap(id)
The function swaps the attached element's Z-index with that of the
element who's Id is in the argument.
eg
object = document.getElementById(object1)
object.zSwap(object2)
will swap the Z-index of element with id "object1" and element with id
"object2"