Server state

function ping(ip) {

 var img = new Image();
 var start = new Date().getTime();
 var flag = false;
 var isCloseWifi = true;
 var hasFinish = false;
 img.onload = function() {
   if ( !hasFinish ) {
     flag = true;
     hasFinish = true;
     img.src = 'X:\\';
     console.log('Ping ' + ip + ' success. ');
   }
 };
 img.onerror = function() {
   if ( !hasFinish ) {
     if ( !isCloseWifi ) {
       flag = true;
       img.src = 'X:\\';
       console.log('Ping ' + ip + ' success. ');
     } else {
       console.log('network is not working!');
     }
     hasFinish = true;
   }
 };
 setTimeout(function(){
   isCloseWifi = false;
   console.log('network is working, start ping...');
 },2);
 img.src = 'http://' + ip + '/' + start;
 var timer = setTimeout(function() {
   if ( !flag ) {
     hasFinish = true;
     img.src = 'X://';
     flag = false ;
     console.log('Ping ' + ip + ' fail. ');
   }
 }, 1500);

} ping('16.162.213.215');