listview - Delete an item in a list permanently by accessing JSON file -

i trying delete item list when user taps on delete button.

i delete item store , item deleted list , however, when re-run application items present .

in order delete items permanently tend think must delete item in json file , how can obtain json string of list , modify it.

i using following code deleting item :

         var store = ext.getstore('mylist');                    store.removeat(index);          this.getlist().refresh(); 

if you're working localstorage, need store.sync() propagate changes store.