fix prosperon layout

examples/pong/main.ce

@@ -23,7 +23,7 @@ function resetBall() {
 
 resetBall()
 
-this.update = function(dt) {
+var update = function(dt) {
   // Move paddles: positive Y is up, so W/↑ means p.y += speed
   if (input.keyboard.down('w')) p1.y += p1.speed*dt
   if (input.keyboard.down('s')) p1.y -= p1.speed*dt
@@ -69,7 +69,7 @@ this.update = function(dt) {
   if (l>config.width) { score1++; resetBall() }
 }
 
-this.hud = function() {
+var hud = function() {
   // Clear screen black
   draw.rectangle({x:0, y:0, width:config.width, height:config.height}, [0,0,0,1])