I need a custom javascript for an online help project

I use a product called MadCap Flare to create online help systems in HTML5. The product comes with a default skin which can only be edited in a few places. However, it is possible to attach a javascript to it that can set new values for the skin in the browser. So far, I have had someone fix most of the things I am looking for, but there are a couple of outstanding issues: * There is a header section that has two built-in divs that are positioned using fixed values. I'd like the script to be able to change these divs so that they use % based values for proper resizing. *The html class of the page has overflow set to hidden, but I want it to be set to scroll *Beneath the header is a table of contents div and a main body div, but they don't clear the header. So if the header size is increased, it overlays the contents and main body. I'd like to make it so that they always come after the header, no matter how big the header is. The person that worked on the script up to now has done a pretty good job, but i think they only know how to append stuff. The bits I need above probably need the script to find certain values in various css files and then apply different values. Is this something you could create a script for?