Error message - please help

I have a project I’m sooo close to finishing, but I’ve run into a problem. I know this error is common, but I don’t know how to solve it, regardless. Here’s the error:

1136: Incorrect number of arguments. Expected 3.

Here is my script:

import gs.TweenLite;
import gs.easing.*;

var photoNums:Array = new Array(photo_1,photo_2,photo_3,photo_4);

var randPhotos:Array;

var currentPhoto:uint = 0;

function shuffle(a:Array):Array 
    var len:Number = a.length-1;
    for (var ivar:Number = len; ivar>=0; ivar--) 
        var p:Number = Math.floor(Math.random()*(ivar+1));
        var t = a[ivar];
        a[ivar] = a[p];
        a[p] = t;
    return a;

randPhotos = shuffle(photoNums);

var timer:Timer =  new Timer(5000);
timer.addEventListener(TimerEvent.TIMER, onTimer);

function onTimer(evt:TimerEvent):void 
    if (currentPhoto > 0) 
    {[currentPhoto]), .5, {x:140, y:0, ease:Back.easeInOut};
    }[currentPhoto+1]), .5, {x:600, y:0, ease:Back.easeInOut};

    currentPhoto += 1;

The error is apparently occurring during the last part of the script, the “TweenLite” statements…

Any chance anyone knows how I can fix this?