Check if var is true from a random object

Seems like I accidently deleted my orginal post and can't recover it ><.

So, I am working on a tic-tac-toe game and I am currently stuck at the last part of the core which is the part that the computer choses a random object (a tile of the platform) to spawn a circle or cross on. But it doesn't know if the tile is already used. In a different script I already have a way to set the tile to used. By checking "var isUsed" to true when hit by a cross or circle.

 var circlePrefab : Transform;
 var crossPrefab : Transform;
 var spawnLocs : GameObject[];
 
 function Update()
 {
     if (CubeSelectScript.madeMoveCircle && MenuButtonScript.playerVsComputer)
     {
         MakeMoveCross();
         CubeSelectScript.madeMoveCircle = false;
     }
     else if (CubeSelectScript.madeMoveCross && MenuButtonScript.playerVsComputer)
     {
         MakeMoveCircle();
         CubeSelectScript.madeMoveCross = false;
     }
 }
 
 function MakeMoveCircle()
 {
     //Spawn circle on random position
     var spawnPos = spawnLocs[(Random.Range(0, spawnLocs.Length))].transform.position;
     Instantiate(circlePrefab, spawnPos, Quaternion.identity);  
 }
 
 function MakeMoveCross()
 {
     //Spawn cross on random position
     var spawnPos = spawnLocs[(Random.Range(0, spawnLocs.Length))].transform.position;
     Instantiate(crossPrefab, spawnPos, Quaternion.identity);   
 }

To Deathcalibur: After compiling with your solution I am getting the following error: "Assets/Standard Assets/Scripts/CubeSelectScript.js(138,10): BCE0089: Type 'CubeSelectScript' already has a definition for 'isUsed'."

CubeSelectScript is the "different script" and line 138 is your "function isUsed()"