Starting a roguelike, maze generator problem.

Hi all,

I'm working on a level generator and, it works exactly how I want it to but it is so very slow it could take up to 10 seconds to generate the map. Is there anywhere that I can speed this script up? Thanks for looking!

 var myX : int;
 var myZ : int;
 var i : int;
 var maxTiles : int;
 var tileSpin : int;
 var tilePrefab : Transform;
 var lastTile : Transform;
 var lookDirection : int;
 var locationVector : Vector3;
 static var tiles : Array;
 
 function Awake()
 {
 tiles = new Array();
 locationVector=(Vector3.zero);
 tilePrefab = Instantiate(tilePrefab,locationVector, Quaternion.identity);
 tiles.push(locationVector);
 }
 function Update()
 {    
     if (i == maxTiles){Destroy(gameObject,0);}
     tileSpin = Random.Range (0,4);
     lookDirection = Random.Range(0,5);
     Builder();
 }    
 function Builder ()
 {
     switch (tileSpin) //rotate the cubes at the right angles
     {
         case (1): tileSpin =  90; break;
         case (2): tileSpin = 180; break;
         case (3): tileSpin = 270; break;
     }
     
     switch (lookDirection) // 4 primaries, I used to have all 8 but it generated ugly and got stuck a lot
     {
         case (1): locationVector = Vector3(myX,  0,myZ+1);break;
         case (2): locationVector = Vector3(myX+1,0,myZ)  ;break;
         case (3): locationVector = Vector3(myX,  0,myZ-1);break;
         case (4): locationVector = Vector3(myX-1,0,myZ)  ;break;
     }    
     for (var a = 0; a < tiles.length; a++)  //  I bet it's in this loop here cause of cycling the array everytime
     {
         if (locationVector == tiles[a])        //  but then... how to accomplish the check?
         {
         myX = locationVector.x;
         myZ = locationVector.z;
         return;
         }
     }
     if (i==maxTiles-1)
     {
         lastTile = Instantiate (lastTile,locationVector, Quaternion.identity);
         tiles.push(locationVector);
         i++;
         return;
     }
     
     tilePrefab = Instantiate (tilePrefab,locationVector, Quaternion.Euler(0, tileSpin, 0));
     myX = locationVector.x;
     myZ = locationVector.z;
     tiles.push(locationVector);
     i++;
 }