Pegar ping

function ping(ip, callback) {
				if (!this.inUse) {
					this.status = 'unchecked';
					this.inUse = true;
					this.callback = callback;
					this.ip = ip;
					var _that = this;
					this.img = new Image();
					this.img.onload = function () {
						_that.inUse = false;
						_that.callback('PING');

					};
					this.img.onerror = function (e) {
						if (_that.inUse) {
							_that.inUse = false;
							_that.callback('PING', e);
						}

					};
					this.start = new Date().getTime();
					this.img.src = "http://" + ip;
					this.timer = setTimeout(function () {
						if (_that.inUse) {
							_that.inUse = false;
							_that.callback('ERRO');
						}
					}, 1500);
				}
			}
			var PingModel = function (servers) {
				var self = this;
				var myServers = [];
				ko.utils.arrayForEach(servers, function (location) {
					myServers.push({
						name: location,
						status: ko.observable('unchecked')
					});
				});
				self.servers = ko.observableArray(myServers);
				ko.utils.arrayForEach(self.servers(), function (s) {
					s.status('checando');
					new ping(s.name, function (status, e) {
						s.status(status);
					});
				});
			};
			var komodel = new PingModel([
				'192.168.1.01', 
				'192.168.0.48', 
				'192.168.0.176'
				]);
			ko.applyBindings(komodel);