doormat works as the user scrolls down the page to the next section. The previous section simply slides up and reveals the next section right under it.
As the user scrolls down and down, new sections are revealed and then slid up in the same manner.
The same effect is applied, but in reverse, when scrolling back up the page, the next section sliding down from the top of the page and covering the previously viewed section.
The effect is widely used in today's Web design market, usually for fixed scrolling, single-page websites.
A demo is included with the download package. Requirements: