it uses min-width and max-width to limit the size. The drawback is that it doesn't work on IE 6-7.. If I remember correctly IE7 have issues while setting min-height on Object Elements and IE doesn't support min-height. at the time I coded swffit other browsers also had issues, see swffit source code for comments about bug fixes.
please note that swffit isn't being maintained anymore: http://www.google.com/url?sa=D&q=http://groups.google.com/group/swffit/browse_thread/thread/5e019d8a1dd47dce&usg=AFQjCNHV0E4heOcXXIr0knE1DNNcazc9Dw
> You received this message because you are subscribed to the Google Groups "SWFFit" group.
> To post to this group, send email to swf...@googlegroups.com.
> To unsubscribe from this group, send email to swffit+un...@googlegroups.com.
> For more options, visit this group at http://groups.google.com/group/swffit?hl=en.