check if there is connection to server

In this example:

dim token as string
token = "&token=sEzwtdFW6v0VIq1c0jIeOzEDNS2xjy"

Dim req As New XMLHTTP60
Dim resp As New DOMDocument60

req.Open "GET", "http://ift.tt/1INEX8L; & token, False
req.send

resp.LoadXML req.responseText

....the question is How to check if it is valid token, because connection with the server depend on a valid token..I want to get a message if not connected to server

check if there is connection to server