try
Dim req = CType(System.Net.WebRequest.CreateDefault(New Uri("http://www.yijiansoft.net:81/srqcx.htm")), System.Net.HttpWebRequest)
req.Method = "HEAD"
req.Timeout = 1000
Dim res As System.Net.HttpWebResponse = req.GetResponse()
output.show(Date.now & "正常")
catch ex As System.Net.WebException
output.show(Date.now & "无反应")
End try