Javascript - Site Preloader

Hi I am looking for someone to put together a Javascript/AJAX site preloader, similar to this: [login to view URL] (click demo to see how it works) I do not want their graphics, I will supply my own. Basically I want a page to appear full black when the user comes to my site, with a simple animated GIF at the top that will wait until the site is fully loaded behind it and then disappear to reveal the site. I do not want a splash page, it has to be a javascript (or something similar) that will help slow-connecting visitors stick around while the page elements and images load behind it. Preloader must function appropriately - for example, if the user has a fast connection or is a repeat visitor (where the images would load from cache and site would load much faster) then the preloader will adjust accordingly (or not appear at all). My site is: www.thesah.net. I already have some javascript that loads on the front page, so it cannot conflict. I have attached my sample of what I want the preloader to look like. If you think you can accomplish this, please PM with your specifics according to this job. Thanks!