You have various options, You can send your data to a service script like PHP with a cool PDF convertion library
Try using AlivePDF( http://alivepdf.bytearray.org/ ). Its pure 100% client side Open Source library for Converting Content to PDF without any need for Server support
Thanks for the recommendation for AlivePDF. It work perfectly, but I have only been able to use it where it creates an Air app. Can it be used in a browser too?