Opinions? Javascript or images?

I'm wondering if anyone can give me an opinion on this. Recently, I was asked to edit our company's website by replacing the left frame with an image and then putting text links on top of the image. They wanted "rollover" links like the IE "hover" effect. Only they're all using Netscape so I couldn't just use the "hover" tag. So I created image rollovers that look like text. Since that time, I've been trying to find a way to make a hover effect that works cross-browser. I finally came up with one, but when I looked at it at home I notice that the script runs slowly on my older computer (sometimes the color change can't keep up with the mouse in Netscape). So I don't know if I'm saving time or not using DHTML. What's less annoying - images that have to preload for rollovers or a script that might work slowly on some people's browsers? I hate making images of plain text because it seems like lots of wasted images. Here's the sample page showing the left frame. This one uses DHTML -- the image rollover version looks exactly the same (assuming you have stylesheets enabled). The layout wasn't my idea, but oh well. Obviously it would look weird if stylesheets were turned off. But image rollovers would look weird too with images turned off! I'd like to hear opinions on this. Which version would you use & why? Here's the source text of the left frame. I'd be interested if anyone knows a way to simplify it so that it works faster. Thanks, Phyllis

P. S. The links on this sample page won't actually work (except for the absolute links) because this page isn't relative to the files I'm linking to (I just put it here as an example).