When a browser requests an ASP page from the Web Server, but does not wait for the entire page to be downloaded, the server continues to process the request, wasting valuable CPU cycles. If your Web Server is Internet Information Server (IIS) 4.0, you can use the Response.IsClientConnected property to determine whether or not the browser is still connected to the server. If it is not connected to the server, you can stop processing to conserve CPU cycles. If you request an ASP page that contains the script below and use PerfMon to monitor the CPU cycles on the Web server, you will notice that if you click ‘stop’ in the browser, the number of CPU cycles will decrease sooner than if the loop had continued.

 <%@ LANGUAGE="VBSCRIPT" %><%Function IsConnectedAfter(Seconds)Dim StartTimeDim PauseTimeIsConnectedAfter = TrueStartTime = NowDo While DateDiff("s", StartTime, Now) < SecondsPauseTime = NowDo While DateDiff("s", PauseTime, Now) < 1'Do NothingLoopResponse.Write "."If Response.IsClientConnected = False thenIsConnectedAfter = FalseExit FunctionEnd IfLoopEnd Function%>