How to use visual_effect on DOM after loading the page?

I would like to make one of the div's hidden while rendring. After page is loaded I would like it to appear on the page using virtual_effect.

I know how to do it in JS / jQuery. Is that possible with pure Ruby code using Prototype?

update_page_tag doesn't really solves the problem It work ok with :开发者_如何学编程highligth, but I can't get it to work with :apper or :slide_down.

---

Well, I spend quite some time looking for the solution and it happen I found it just after submitting the question here. :-)

The problem was, that I was calling update_page_tag right in the same helper I was generating the problematic div. I wasn't concat'ing, so the update code was replacing the content_tag.