a snippet for testing whether you could visit twtter or facebook

var Leeiio = {};
Leeiio.isFucked;
 
Leeiio.fuck = function(){
    var imgUrl = "http://twitter.com/favicon.ico?"; //You can change it to "http://www.facebook.com/favicon.ico?"
    imgUrl += new Date().getTime(); //add Time stamp to prevent the Browser's cache
    function removeElement(_element){
         var _parentElement = _element.parentNode;
         if(_parentElement){
                _parentElement.removeChild(_element);
         }
    }
    function testImg(isrc){
        var fuckimg = document.createElement('iframe'); //I used to createElement('img') but it have some problem in webkit
        fuckimg.src = imgUrl;
        fuckimg.style.cssText = "display:none";
        document.body.appendChild(fuckimg);
        fuckimg.timer = setTimeout(function(){
            alert("Fuck it!(You know fuck what right?)");
            fuckimg.src = null;
            fuckimg.onload = null;
            removeElement(fuckimg);
            Leeiio.isFucked = true;
        }, 3290);   //set timeout to connect to twitter
        fuckimg.onload = function (){
            clearTimeout(this.timer);
            alert("Nice!You are free man!");
            fuckimg.src = null;
            fuckimg.onload = null;
            removeElement(fuckimg);
            Leeiio.isFucked = false;
        }
    }
    testImg(imgUrl);
}
Leeiio.fuck();
 
var timeTest = setTimeout(function(){
    if(!Leeiio.isFucked){
        //add your code here that you want to
        alert('Fuck!');
    }
    clearTimeout(timeTest);
},4000);