I agree with the boolean type variables. They are much more efficient. However, it is standard javascript that nothing be capitalize, NEVER. This is to avoid the confusion of having to remember "Left" is capital L, not lowercase. And face it, after calling it enough times you're inevitably going to forget to hit the shift key. By leaving everyting lowercase, this is never an issue. The only time I ever capitalize is when a variable is a combination of two words, like in the method "getElementById". If you notice, all javascript methods and properties work this way so by following the same pattern there is no confusion.