How come two of my parameters are undefined when I try to pass them in?

[igkman]

var group1PixelLocations = {
		'x' : [game.width/2,game.width/2-30,game.width/2,game.width/2-30,game.width/2,game.width/2-30],
		'y' : [(game.height/2)-30,(game.height/2)-60,(game.height/2)-90,(game.height/2)-120,(game.height/2)-150],
		
	};
	
	//create enemies
	for (var i = 0; i < 5; i++) {		

enemies.create(game.add.enemy(game.width/1.33,0,group1PixelLocations.x[i],group1PixelLocations.y[i]));	
	}

The last two parameters of game.add.enemy() ,xPix and yPix, are undefined when I try to pass them unto my Enemy Class:

var Enemy = function(game,x,y,xPix,yPix) {
    Phaser.Sprite.call(this,game,x,y,'');
    // for some reason, xPix and yPix are undefined

    alert(xPix + ' ' + yPix);
    this.create();
    
}

Enemy.prototype = Object.create(Phaser.Sprite.prototype);
Enemy.prototype.constructor = Enemy;

var completed = false;
Enemy.prototype.preload = function() {

}

Enemy.prototype.create = function() {

        var enemySprites = ['enemy1','enemy2','enemy3'];
        // enemy sprite and its animation
        this.enemy = game.add.sprite(this.x,this.y,enemySprites[0]);
        this.enemy.anchor.set = 0.5;
        this.enemy.animations.add(enemySprites[0],null,10,true);
        this.enemy.animations.play(enemySprites[0]);

        //This will be tracked by the enemy sprite
        //will be set to invisible
        this.pixel = game.add.sprite(this.xPix,this.yPix,'pixel');
        //this.pixel.visible = false;
        /*alert(this.xPix+ ' ' + this.yPix);*/

        game.physics.arcade.enable(this.enemy);
        game.physics.arcade.enable(this.pixel);    
        
        this.sideTween();
        this.group1Path();
        
}


Enemy.prototype.update = function() { 

        if (!this.exists)    return;

        if (completed)
        game.physics.arcade.moveToObject(this.enemy,this.pixel,100);
}

/*the path of pixel
moves back and forth
represents the movement of enemy sprites
while enemies are flying in*/
Enemy.prototype.sideTween = function() {

        this.tween = game.add.tween(this.pixel).to({x: this.xPix + 400}, 2000, null,-1,true);
        this.tween.yoyo(true,0,0);
        this.tween.repeat(-1);
        this.tween.start();
}