var currCol = 1;
function scrollSubmissionsLeft() {
	if ( currCol < numColumns ) {
		new Effect.Move($('submission_thumbs'), { x: -200, y: 0, mode: 'relative', duration: .5 });
		currCol++;
	}
}
function scrollSubmissionsRight() {
	if ( currCol > 1 ) {
		new Effect.Move($('submission_thumbs'), { x: 200, y: 0, mode: 'relative', duration: .5 });
		currCol--;
	}
}