var CloseWindow = Class.create();
CloseWindow.prototype = {
    initialize: function(className, parentElement) {
        var elements = document.getElementsByClassName(className, parentElement);
        for (var i = 0, len = elements.length; i < len; i++) {
            Event.observe(elements[i], 'click', this.addCloseEvent.bindAsEventListener(this));
            Event.observe(elements[i], 'keypress', this.addCloseEvent.bindAsEventListener(this));
        }
    },
    addCloseEvent: function() {
        window.close();
    }
};


Event.observe(window, 'load', function () {
    new CloseWindow('cw');
});