Flash Action Script 3.0 error 1120 - actionscript-3

Question

So I have come to a point where I have to ask a question, I've already went to 3 pages of google for hours now. I hope you guys can help me out.
I'm pretty sure i've defined var UsedSlot but it says error 1120.
i've already tried putting it on different lines, like before and after the timer. I'm just a newbie and I need this for my term project.
Here are the errors
Scene 1, Layer 'Player', Frame 1, Line 55 1120: Access of undefined property UsedSlot.
Scene 1, Layer 'Player', Frame 1, Line 62 1120: Access of undefined property UsedSlot.
Scene 1, Layer 'Player', Frame 1, Line 90 1120: Access of undefined property UsedSlot.
Scene 1, Layer 'Player', Frame 1, Line 91 1120: Access of undefined property UsedSlot.
stop();
import flash.display.MovieClip;
import flash.events.Event;
import fl.motion.MotionEvent;
import flash.utils.Timer;
import flash.events.TimerEvent;
//initialize objects
var PlayerItems:Array = [new Items_Player_Cheese(),
new Items_Player_Cheese(),
new Items_Player_Cheese(),
new Items_Player_Cheese(),
new Items_Player_Cheese(),];
//hard code test ***working***
/*PlayerItems[0].x = Guide_Test_Start.x;
PlayerItems[0].y = Guide_Test_Start.y;
stage.addChild(PlayerItems[0]);*/
///////////////////
var j:int;
var SlotUsed:Array = new Array(PlayerItems.length);
for(j = 0 ; j < SlotUsed.length; j++)
{
SlotUsed[j] = -1
trace(SlotUsed[j]);
}
for(j = 0; j < PlayerItems.length; j++)
{
PlayerItems[j].x = Guide_Test_Start.x;
PlayerItems[j].y = Guide_Test_Start.y;
}
var PlaceOccupied:Array = [false,false,false,false,false];
//check if a place is unoccupied
var myTimer:Timer = new Timer(3000);
myTimer.addEventListener(TimerEvent.TIMER, CheckVacancy);
myTimer.start();
//choose a starting location
var CVSync:int;
function CheckVacancy(e:TimerEvent)
{
for(CVSync = 0 ; CVSync < 5; CVSync++)
{
if(PlaceOccupied[CVSync] == false)
{
// Put an object
var ItemIndex = randomRange(0,PlayerItems.length - 1);
while(UsedSlot[ItemIndex] > -1)
ItemIndex = randomRange(0,PlayerItems.length - 1);
trace("Item["+ItemIndex+"] placed on ["+CVSync+"]");
PlayerItems[ItemIndex].x = StartGuide[CVSync].x;
PlayerItems[ItemIndex].y = StartGuide[CVSync].y;
UsedSlot[j] = ItemIndex;
PlaceOccupied[CVSync] = true;
trace("Vacant Slot Filled" + getTimer() + " ms");
break;
}
}
}
//Instantiate the objects
for(j = 0; j < PlayerItems.length; j++)
{
trace("Adding Player Items");
stage.addChild(PlayerItems[j]);
}
//Add Listener To determine A hit
for(j = 0; j < PlayerItems.length; j++)
{
PlayerItems[j].addEventListener(MouseEvent.MOUSE_UP, MUp);
}
function MUp(e:MouseEvent):void
{
for(j = 0; j < PlayerItems.length; j++)
{
if(PlayerItems[j].hitTestObject(MyItem[0]))
{
CVSync[UsedSlot[j]] = false;
UsedSlot[j] = -1;
PlayerItems[j].x = -100;
trace("Point by: " + MyItem[0].name.toString());
break;
}
}
}
/*cheese.addEventListener(MouseEvent.MOUSE_UP, MUp);
function MUp(e:MouseEvent):void{
if(cheese.hitTestObject(MyItem[0]))
{
trace("Cheese Eaten by: " + MyItem[0].name.toString());
cheese.x = Guide_Test_Start.x;
cheese.y = Guide_Test_Start.y;
}
}*/
function randomRange(minNum:Number, maxNum:Number):Number
{
return (Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum);
}

Answer 1

I'm pretty sure i've defined var UsedSlot
No, you don't and that's the problem here.
The name UsedSlot appears 4 times in the snippet you posted, which are the lines that cause the 4 errors.
None of them defiens the variable.
You do however define another variable:
var SlotUsed:Array
in your code.
If this is unclear: these are two different variables. Just because you define a variable SlotUsed somewhere in your code doesn't mean you can access it via some other name, like UsedSlot.
This is case sensitive, which means SlotUsed and slotUsed are not considered to be the same.
As an advice, "being pretty sure" is usually worthless when it comes to finding problems like this. Instead, prove it by finding the declaration. If you cannot find it, it's probably not there. After all, the compiler cannot find it.
It's a common convention to start variable names with a small letter, which helps to distinguish them from names of classes (or interfaces...).
While it's your choice to code however you want, it's easier for others to read your code if you stick to common conventions and therefore simplifies the task of helping you out. =)