Frontpage / Firefox Compatibiity unwanted overlapping text graphics when viewed on Firefox

[entoman 0]

Hello

My website http://www.learnaboutbutterflies.com/ looks perfect when viewed on my PC using Internet Explorer 8. It also looks perfect on some other PCs using IE6. Unfortunately when viewed on Firefox and some other clients the website reproduces with blocks of text and / or graphics overlapping or seriously misplaced. My website has over 600 pages so correcting ( if it is possible ) the pages is a major hassle, especially as the site is not written in CSS.

Question 1 - Can this overlap problem be cured within FrontPage ( how ? ) or is it an inherent compatibility problem requiring new software ?

Question 2 - If I need to replace FrontPage with another web creation program to cure this overlap problem, can I copy my existing html files and JPEGs into the other program ( e.g. Microsoft Expression Web 2, Serif WebPlus etc ), and will I then be able to easily amend or correct the files to make my website compatible with Firefox, early versions of IE, etc ?

Many thanks
entoman