Spawning enemies in waves

Hi,

I am trying to make a spawn system in waves. My spawn is working but the wave section is not.

Once one enemy dies, enemies are just randomly spawn out of control

 var location:Transform;
 var enemySelect:Rigidbody2D;
 var spawn1:Transform;
 var spawn2:Transform;
 var spawn3:Transform;
 var waveTime:float;
 var waveLevel:int = 1;
 var totalEnemy:int = 2;
 var enemyAlive:int = 0;
 var waitToWave:float = 10;
 var waveMultiplier:int = 2;
 var enemy1:Rigidbody2D;
 var enemy2:Rigidbody2D;
 var enemy3:Rigidbody2D;
 
 
 function Awake () 
 {
     Spawn();
     //enemyCount = GameObject.FindGameObjectsWithTag("Enemy");
 //var tempobj : GameObject = GameObject.FindWithTag("Enemy");
 var countScript : EnemyHealth = GetComponent(EnemyHealth);
 
 }
 
             
 
 
 
 function FixedUpdate () {
 
 
       
      
     if (enemyAlive == 0) { 
         //the is no creature left; create a wave!
         waveLevel++;
         totalEnemy = totalEnemy * waveMultiplier;
         Spawn();
         }
         
         if (EnemyHealth.health == 0){
         enemyAlive--;
        
      Debug.Log("enemy died");
      }
      }
      
         
     
     
     
     if (waitToWave <= waveTime) {
         waveTime = 0; 
         //reset time
         //enemyAlive = totalEnemy;
         
      }
      
      
 
     
     
             function Spawn() 
     {
   
      for(var i:int=0; i<totalEnemy; i++) {
             enemyAlive++;
      //select a random number, inside a maths function absolute command to ensure it is a whole number
      var randomPick:int = Mathf.Abs(Random.Range(1,3));
      
      
      
      //create a location 'Transform' type variable to store one of 3 possible locations declared at top of script
      var location1:Transform;
      location1 = spawn1;
      
      var location2:Transform;
      location2 = spawn2;
      
      var location3:Transform;
      location3 = spawn3;
      
      if(randomPick == 1){
       location = location1;
       Debug.Log("Choose loc 1");
      }
      else if(randomPick == 2){
       location = location2;
       Debug.Log("Choose loc 2");
      }
      else if(randomPick == 3){
       location = location3;
       Debug.Log("Choose loc 3");
      }
      //select a random number, inside a maths function absolute command to ensure it is a whole number
      var randomPickEnemy:int = Mathf.Abs(Random.Range(1,4));
      
 
      //check what randomPick is, and select one of the 3 locations, based on that number
      if(randomPickEnemy == 1){
       enemySelect = enemy1;
       Debug.Log("Choose enemy 1");
      }
      else if(randomPickEnemy == 2){
       enemySelect = enemy2;
       Debug.Log("Choose enemy 2");
      }
      else if(randomPickEnemy == 3){
       enemySelect = enemy3;
       Debug.Log("Choose enemy 3");
      }
      
      
      
      
      //create the object at point of the location variable
      var thingToMake:Rigidbody2D;
      Debug.Log(location);
      thingToMake = Instantiate(enemySelect, location.position, location.rotation);
      thingToMake.AddForce(Vector3(0,0,100));
      
      
      //halt script for 1 second before returning to the start of the process
      yield WaitForSeconds(5);
 
     }
     }

I have tried for hours trying to move loops around,brackets etc. but all has failed

what am i doing wrong?