Forum Moderators: not2easy
Are you testing first in Firefox, then in Internet Explorer? You won't want to do it the other way around (too frustrating). Firefox is more insistant that you follow web standards, so code that works on Firefox is more likely to work on other browsers.
Run a validation test on your page with w3.org's html validator. You'll find a number of errors. Any of these could be causing the problems.
[validator.w3.org...]