var fieldArr = [SKSpriteNode]()
for var i = 0; i < 13; i++ {
for var j = 0; j < 12; j++ {
var x_current = CGFloat(20 * i)
var y_current = CGFloat(20 * j)
fieldArr.append(SKSpriteNode(imageNamed: "field"))
fieldArr[i].size = CGSize(width: 20, height: 20)
fieldArr[i].position = CGPointMake(x_current, y_current)
self.addChild(fieldArr[i])
}
}