backbutton confirm exit app android + phonegap + jquery

document.addEventListener("deviceready", onDeviceReady, false);

function onDeviceReady(){
    document.addEventListener("backbutton", function(e){
       if($.mobile.activePage.is('#homepage')){
           e.preventDefault();
           navigator.app.exitApp();
       }
       else {
           navigator.app.backHistory();
       }
    }, false);
}

$('#staticsPage').on('pageshow', function(){
    alert(staticsPage Init);
    init_statistics();
});

document.addEventListener("deviceready", appReady, false);

//HANDLE BACK BUTTON
function appReady()
{   
    document.addEventListener('backbutton', function(e){
        var activePage = $.mobile.activePage.attr('id');

        if(activePage == 'menuPage')
        {
            e.preventDefault();
            navigator.app.exitApp();
        }
        else if(activePage == 'staticsPage')
        {
            e.preventDefault();
            $.mobile.changePage('#menuPage');
        }
        else 
        {
             navigator.app.backHistory();
        }
    }, false);
}

function onDeviceReady(){
    document.addEventListener("backbutton", function(e){
       if($.mobile.activePage.is('#homepage')){
           e.preventDefault();
           navigator.app.exitApp();
       }
       else {
           navigator.app.backHistory()
       }
    }, false);
}

    <feature name="App">
        <param name="android-package" value="org.apache.cordova.App" />
    </feature>