gistfile1.js

		var mousewheel_handler = (function() {
			var threshold = 0.75,
				scrolled_amount = 0;

			return function(e, delta, deltaX, deltaY) {
				scrolled_amount += deltaY;
				
				if (scrolled_amount > threshold) {
					move.up();
					scrolled_amount = 0;
				} else if (scrolled_amount < -threshold) {
					move.down();
					scrolled_amount = 0;
				}
				
			};
		})();