use 'width' and 'height' URL parameters to change both, there is a recursion limit :)
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | | | | | | | + + +--+--+ + + + +--+ + +--+ + + + + | | | | | | | | | | | | + +--+--+ + +--+--+ + +--+ + +--+ + +--+ | | | | | | | | + +--+--+--+--+--+ +--+ + +--+--+--+--+--+ + | | | | | | | | | + + + + + + +--+ +--+--+ +--+--+ + + + | | | | | | | | | | | +--+--+--+ + +--+ +--+ + +--+--+ + + +--+ | | | | | | | | | + + +--+ +--+ + + +--+ +--+ +--+--+--+ + | | | | | | | | | | | | + + + +--+ + +--+--+ +--+ +--+--+ + + + | | | | | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+