Javascript: hide/show content with css tabs

[whyiteasy]

I've been trying to get this to work all day and I'm 95% there! Can someone please look at my code and help me with one (hopefully simple) thing? I've got 3 CSS tabs that change style when clicked (active vs. inactive) and shows the corresponding div content below. Everything is working (at least in Firefox) but what's got me annoyed is that the code I got (from http://www.digimantra.com/tutorials/simple-tabs-using-javascript-and-css/) uses