The IsClientConnected property is a read-only property that indicates if the client has disconnected from the server since the last Response.Write.
Response.IsClientConnected ( )
This property allows you greater control over circumstances where the client may have disconnected from the server. For example, if a long period of time has elapsed between when a client request was made and when the server responded, it may be beneficial to make sure the client is still connected before continuing to process the script.
<%
'check to see if the client is connected
If Not Response.IsClientConnected Then
'get the sessionid to send to the shutdown function
Shutdownid = Session.SessionID
'perform shutdown processing
Shutdown(Shutdownid)
End If
%>