Editing gifs in photoshop 7?

I have a fairly outdated version of photoshop (I mean, it comes with imageready... that should tell you something) and I've been working on making graphics. Unfortunately creating adjustment layers isn't an option for this version and I was wondering if there's a way to make gifs brighter with photoshop 7. would I have to tweak each frame individually to get the saturation/brightness/etc I want or is there something I've just been missing? I'm pretty new to this, as you can probably tell, and have been trying to teach myself.