This is a web game using cocos2d-html5.

I have a game layer and I want to handle mouseover event inside:

var GameLayer = cc.Layer.extend({
    init:function () {
        // ......
        this.curPosition = null;
        if( 'mouse' in sys.capabilities ) {
            //this.setMouseEnabled(true);
            this.mouseCaptured = false;
            canvas = document.getElementById('gameCanvas');
            canvas.addEventListener('mousemove', function(evt) {
                var rect = document.getElementById('gameCanvas').getBoundingClientRect();
                var curPos = new cc.Point();
                curPos.x = evt.clientX - rect.left;
                curPos.y = evt.clientY - rect.top; 

                // the problem is here,  this is wrong since "this" stands for canvas here
                this.curPosition = curPos
                // also wrong
                this.updatePosition(curPos);
            }, false);
        }
        // ......
    },
    updatePosition:function (position) {
        this.currentPosition = position;
        // ......
    }
});

var HelloWorldScene = cc.Scene.extend({
    onEnter:function () {
        this._super();
        var layer = new GameLayer();
        layer.init();
        this.addChild(layer);
    }
});

All I want is to call functions or set class variable inside the listener.

Hope someone can give a hint, thanks :)

you can use

init:function () {
    var self=this;
    //......

Then you can call the class-functions inside the listener with

canvas.addEventListener('mousemove', function(evt) {
            self.updatePosition(1);
            // ....