大家帮帮忙,我这样继承cc.LabelAtlas哪里出错了呢

var FifoLabelAtlas = cc.LabelAtlas.extend({
ctor: function (strText, charMapFile, itemWidth, itemHeight, startCharMap) {
this._super(strText, charMapFile, itemWidth, itemHeight, startCharMap);
}

});
FifoLabelAtlas.charMapFile = null;
FifoLabelAtlas.itemWidth = null;
FifoLabelAtlas.itemHeight = null;
FifoLabelAtlas.startCharMap = null;

FifoLabelAtlas.initStatic = function(charMapFile, itemWidth, itemHeight, startCharMap){
FifoLabelAtlas.charMapFile = charMapFile;
FifoLabelAtlas.itemWidth = itemWidth;
FifoLabelAtlas.itemHeight = itemHeight;
FifoLabelAtlas.startCharMap = startCharMap;
},

FifoLabelAtlas.create = function(text,relativePos,parent,zorder){
var ret = new FifoLabelAtlas(text,FifoLabelAtlas.charMapFile,FifoLabelAtlas.itemWidth,FifoLabelAtlas.itemHeight,FifoLabelAtlas.startCharMap);
ret.attr({
anchorX: 0.5,
anchorY: 0.5,
x:cc.winSize.width * relativePos.x,
y:cc.winSize.height * relativePos.y
});
parent.addChild(ret,zorder);
return ret;
}

调用方式如下:
FifoLabelAtlas.initStatic(res.map_num_pink,704/22, 37, ‘%’);

var x = 0.5;
var y = 0.5;
var labelAtlas = FifoLabelAtlas.create(“00:00”,cc.p(x,y),this,this.getLocalZOrder());
html5 可行,但是win32下一闪而过。