Parse a .Net Page with Postbacks

I need to read data from an online database that’s displayed using an aspx page from the UN. I’ve done HTML parsing before, but it was always by manipulating query-string values. In this case, the site uses postbacks. So, you click on a value in box one, then box two shows, click on a value in box 2 and click a button to get your results.

BeautifulSoup Grab Visible Webpage Text

Basically, I want to use BeautifulSoup to grab strictly the visible text on a webpage. For instance, this webpage is my test case. And I mainly want to just get the body text (article) and maybe even a few tab names here and there. I have tried the suggestion in this SO question that returns lots of <script> tags and html comments which I don’t want. I can’t figure out the arguments I need for the function findAll() in order to just get the visible texts on a webpage.