I want to know how i can read the status of my preferences.xml checkbox using appcelerator titanium

I'm using Titanium Appcelerator to build a App for Android. And i have succeeded in creating a preference screen with the preferences.xml below. I'm trying to figure out how i can see if the checkbox is selected or not.

 <?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
android:title="Instellingen kortingen">
<PreferenceCategory android:title="Plaats">
    <CheckBoxPreference
        android:title="Almere"
        android:defaultValue="false"
        android:key="checkbox" />
    <CheckBoxPreference
       开发者_如何学运维 android:title="Amsterdam"
        android:defaultValue="false"
        android:key="checkbox" />
    <CheckBoxPreference
        android:title="Lelystad"
        android:defaultValue="false"
        android:key="checkbox" />  
    <CheckBoxPreference
        android:title="Utrecht"
        android:defaultValue="false"
        android:key="checkbox" />          
</PreferenceCategory>

I believe it can be treated as a property where you do a Ti.App.Properties.getString('Utrecht') OR Ti.App.Properties.getBool('Utrecht')

see this also http://developer.appcelerator.com/question/99541/where-is-android-app-property-list-in-emulator