getElementById to return the DOM object of a dynamically created element doesn’t mean Internet Explorer will be able to manipulate it in all cases. Sometimes it just says no.overflow:hidden can be used to crop a 200×300px SWF file to show just the important part unless Firefox on OS X support is required. In this case the overflow:hidden part will be ignored and the SWF will render as an absolutely positioned element breaking the document flow and overlapping any element below it.