@Xom Adept: Thanks! It's always good to be reminded that not everyone's keyboard looks the same. And just to add to that, I actually mouse left handed, so even though my keyboard does have a WASD layout, it's kind of uncomfortable to use and I typically prefer the arrow keys.
@mnilsson: 'the browser interprets the down key as scroll down the page', I have actually had this problem in HTML5 games before too. :(
@Spring-Enterprises: Now that's living the dream! ;)