Topic: dynamic screenshots for web application

I need a script or program that will generate screenshots for every page in my company's web application. Ideally, when I run it it will update all of the screenshots that have changed due to code changes.

currently I am trying to do this with silktest and it is an uphill battle. the application is jsp generated and depending on your user level, different things appear, so I need the ability to log in. there are many javascript links that open new windows or require certain fields to be filled in. there are multiple ways of getting to some pages but I only want one screenshot for each page so I need some way of recognizing pages.

silktest is very bad at dealing with dynamic browsing - is there a better solution?

has anyone done anything similar? any suggestions for a better program/approach? anyone tried something like this in silktest?
I would be extremely helpful for any advice/help!