[Moo] Cannot stop event beforeunload

[Sitthykun LY]

cool,

Please help me to work with beforeunload event

var testClass = new Class({
     initialize: function() {
        this.onLoad();
     },

    onLoad: function() {
       this.closeForm();
    },

    closeForm: function() {
         window.addEvent('beforeunload', function(event){
              event.stop(); /// it does not work
              this.showMsg();
         }.bind(this));
  },

  showMsg: function() {
      .....
 }

});


//---------------------------------

window.addEvent('beforeunload', function(event){
             * event.stop(); /// it does not work*
              this.showMsg();
         }.bind(this));



-- 
Best regards,
Sitthykun LY