text: var config_default = {
  	documentTitle : "Greeting Card",
  	stageW : 800,
  	stageH : 480,
  	col : 40,
  	row : 24,
  	emitterNum : 10,
  
  	preface : [
  		"Tap to open my greeting card~",
  		"Well, continue~",
  		"Don't stop tapping until you know my meaning ^_^"
  	],
  	prefaceFontSize: 20,
  
  	colorList : [
  		"#990000",
  		"#FF0000",
  		"#CC3300",
  		"#CC6600",
  		"#CC0033",
  		"#FFFF00",
  		"#33FF00",
  		"#33CC00",
  		"#0066FF",
  		"#00FF99",
  		"#770099"
  	],
  
  	matrix : null
  };
  
  
  function normalizeConfig (_config) {
  	if (_config === null) {
  		_config = {};
  	}
  
  	for (var k in config_default) {
  		if (typeof _config[k] === "undefined") {
  			_config[k] = config_default[k];
  		}
  	}
  
  	return _config;
  }