anchor.diff:  
     void _changeSelection(int area, int level) {
       if (area < 0) area = 0;
  -    if (area >= content.areas.length) {
  -      area = content.areas.length - 1;
  +    if (area >= _openAreas) {
  +      area = _openAreas - 1;
       }
   
       selectedArea = area;
  
positive.code:   final Storage storage;
    int selectedArea = 0;
    int selectedLevel = 0;
  
    SelectLevelScreen(this.content, this.save, this.storage);
  
  
negative.code:         }
  
          // Can only select one past the completed level.
          if (i >= _openAreas || level > getCompletedLevel(area)) {
            fore = Color.DARK_GRAY;
          }
  
  