Creating a preloader based on the source code you provided should be fairly straightforward, as [login to view URL] provides a pretty clear idea of what's expected from the class. I'd be happy to help!
Relevant Skills and Experience
JavaScript tends to be my language of choice and is easily what I have the most experience in. Likewise, most of the JavaScript jobs I take on are browser based, so this job feels like a perfect fit.
Proposed Milestones
$80 USD - Deliver completed preloader class code
Besides being simple, short, commented, and (obviously) working, is there anything else specific that you'd want me to include?