var duesidFacebook = '';
var duesfbuuid = ''; 

FB_RequireFeatures(["XFBML","CanvasUtil","Api","Connect"], function(){
    FB.init("9227580a28566ce536b9b4fb3e90d4d2","http://www.2spaghi.com/facebook/xd_receiver.html");
});

function duesLogout(url){
    
    if (duesfbuuid!='' && duesfbuuid ==  duesidFacebook){
       
        FB.ensureInit(function(){
           
            FB.Connect.logout(function(){ 
                
                window.location.href=url;
            });
        });
    }else {
        window.location.href=url;
    }
}