Javascript causing freezing

[Traveller]

Hi All.

The computer is on W98SE and the browser is Firefox.

It freezes every few seconds and requires a reboot whenever a webpage with javascript is viewed. The problem is that in some webpages, the thing I want to see/use doesn't work without javascript, e.g. a photo, but how do I allow the photo (for example) to load but prevent all the other billions of things on the same page that uses javascript such as banners and ads, etc?

Does Firefox use it's own built in javascript program? If not, where do I go to look at the more advanced settings for javascript. I know the J2SE Runtime Environment appears in add/remove list.

How do I do the same for Flash stuff?

Thanks.