Extメモリ最適化

Ext.apply(Ext.QuickTips, {
   destroy : function(){
        this.unregister();
        Ext.destroy(this.getQuickTip()); 
   }
});

Ext.EventManager.on(window,   "beforeunload",  Ext.QuickTips.destroy ,Ext.QuickTips,{single:true});
//or equivalent

 
 
Funtions in JavaScript are lexically rather than dynamically scoped.This means that the y run in the scope in the which the y are defined,not the scope from which they the exted.