判断计算机是否联网
判断电脑是否联网
function isOnline(){
var img = new Image();
img.id = "test_is_online";
img.onload = function(){
document.body.removeChild(
document.getElementById("test_is_online"));
};
img.onerror = function(){
document.body.removeChild(
document.getElementById("test_is_online"));
alert("断网了！");
};
img.src = "http://www.baidu.com/img/baidu_jgylogo3.gif";
img.style.display = "none";
document.body.appendChild(img);
};window.onload = function(){
setInterval(isOnline, 10000);
};