UPDATE: I have updated the code and the post here, I have optimized and narrowed down the number of lines, the new demo is up and running.
I use to use something similar to this on my older site to bring down content and a contact form on one side using jQuery, then about a year later I was thinking why not bring it back up, change some styles, and write a post for others to use. The concept is pretty simple.
When you press the selector, it will slide down panel 1, then using window.setTimeout, we will call the panel 2 to come down 100ms later, just enough of a delay where we get a nice effect. Once the panels slide down, the content within are faded in using fadeIn(); To close the panels we call a closePanels() that does the opposite effect when it is sliding down.