Pas bô

var point = function(X, Y) {
    this.X = X;
    this.Y = Y;
}
point.prototype = {
    add: function(point_value) {
        this.X += point_value.X;
        this.Y += point_value.Y;
    },
    clone: function() {
        return new point(this.X, this.Y);
    }
};