JoeyRen

solved this problem. I forgot to reset the counter. thanks

As I kept clicking "next" button, TweenMax was logging this error 'Uncaught Cannot tween a null target.' but the array did actually exist. what is the reason for this?

solve the problem thanks a lot.

we can use index & target parameters to log information easily var ani = TweenLite.to(boxes, .5, { left: function(index, target){console.log(index, target); return Math.random() * 100;} }) Is there any way to pass these two parameters into onComplete function like this: var ani = TweenLite.to(boxes, .5, { left: '+=30px', onComplete: function(){console.log(index, target);}, onCompleteScope: [index, target] })