Global.asa

<Script Language = "VBScript"  RunAt = "Server">
Sub Application_OnStart()
    Application("ActiveUsers") = 0
End Sub
Sub Session_OnStart()
    Session.Timeout = 20
    Application.Lock
    Application("ActiveUsers") = Application("ActiveUsers") + 1
    Application.UnLock
End Sub
Sub Session_OnEnd()
    Application.Lock
    Application("ActiveUsers") = Application("ActiveUsers") - 1
    Application.UnLock
End Sub
</Script>

Global.asa要放在根目录

<%
Response.Write "<center>如何统计在线人数</center><P>"
Response.Write "当前在线人数为："&Application("ActiveUsers")
%>