从phonegap返回值确认回调函数到调用函数

Question

如何从phonegap确认回调函数到调用函数的返回值。我想通过回调函数返回sureDelete。

var DeleteGroup= function(){

    var sureDelete;
    var render = function() {        
        promptfun();
        return sureDelete;
     };

     var promptfun = function(){
         navigator.notification.confirm(
             'Are you sure you want to delete group?',
              confirmHandler,
             'Delete Group',      
             ['Cancel','Delete']  
         );
     };

     var confirmHandler = function(buttonIndex){
         if(buttonIndex == 2){
             sureDelete = true;
         }else{
             sureDelete = false;
         }
     };

     return {
         render:render
     };
};