diff --git a/src/main/scala/conways/ConwaysGameProcessing.scala b/src/main/scala/conways/ConwaysGameProcessing.scala
index 0564de4..7c92da3 100644
--- a/src/main/scala/conways/ConwaysGameProcessing.scala
+++ b/src/main/scala/conways/ConwaysGameProcessing.scala
@@ -18,14 +18,14 @@ object ConwaysGameProcessing extends App {
 class ConwaysGame extends PApplet {
   val black = 0
   val white = 255
-  val screenSize = 1000
+  val screenSize = 500
 
   var current = new Grid(20)
   var started = false
-  var boxThickness = screenSize / current.size
+  def boxThickness = screenSize / current.size
 
   override def setup() = {
-    frameRate(10)
+    frameRate(20)
     size(screenSize, screenSize)
     background(0)
   }
@@ -38,7 +38,6 @@ class ConwaysGame extends PApplet {
   }
 
   def drawGrid() {
-    boxThickness = screenSize / current.size
     background(0)
     current.liveCells.foreach {c =>
       fill(white)
@@ -57,6 +56,6 @@ class ConwaysGame extends PApplet {
   }
 
   override def keyPressed(e: KeyEvent) {
-    started = true
+    started = !started
   }
 }
\ No newline at end of file
diff --git a/src/main/scala/conways/Grid.scala b/src/main/scala/conways/Grid.scala
index 8d9e456..02291ef 100644
--- a/src/main/scala/conways/Grid.scala
+++ b/src/main/scala/conways/Grid.scala
@@ -28,13 +28,15 @@ class Grid(minSize: Int) {
   }
   
   def fit {
-    val xMin = liveCells.map(_.x).min
-    val yMin = liveCells.map(_.y).min
-    if (xMin < 0 || yMin < 0) {
-      liveCells = liveCells.map(e => Cell(e.x - xMin, e.y - yMin))
-    }
-    if ((xMin > 0 || yMin > 0) && size > minSize) {
-      liveCells = liveCells.map(e => Cell(e.x - (xMin - 1), e.y - (yMin - 1)))
+    if (!liveCells.isEmpty) {
+	    val xMin = liveCells.map(_.x).min
+	    val yMin = liveCells.map(_.y).min
+	    if (xMin < 0 || yMin < 0) {
+	      liveCells = liveCells.map(e => Cell(e.x - xMin, e.y - yMin))
+	    }
+	    if ((xMin > 0 || yMin > 0) && size > minSize) {
+	      liveCells = liveCells.map(e => Cell(e.x - (xMin - 1), e.y - (yMin - 1)))
+	    }
     }
   }
 }