var MyFileObject = Server.CreateObject("Scripting.FileSystemObject");
给你一个最全的吧：
<script language = "vbscript" runat = "server">
sub application_onstart
'取的计数文件的真实路径
countfile=server.mappath("count.txt")
'创建文件系统对象实例
set myfso = server.createobject("scripting.filesystemobject")
'若计数文件不存在
if not myfso.fileexists(countfile) then
'创建该文件及取得textstream对象实例
set mytextstream = myfso.createtextfile(countfile, True)
application.lock
application("online") = 0
application("counter") = 0
application.unlock
'将计数值写入文件
mytextstream.writeline(cstr(application("counter")))
else
'以只读的方式打开
set mytextstream = myfso.opentextfile(countfile,1,false)
'读一行，并将值赋给计数变量
application("counter") = mytextstream.readline
end if
mytextstream.close
set myfso = nothing
end sub
sub session_onstart
session.timeout = 1
countfile = server.mappath("count.txt")
set myfso = server.createobject("scripting.filesystemobject")
application.lock
application("online") = application("online")+1
application("counter") = application("counter")+1
application.unlock
'以写方式打开文件
set mytextstream = myfso.opentextfile(countfile,2,false)
'以写行的方式将数据写入文件
mytextstream.writeline(cstr(application("counter")))
mytextstream.close
set myfso = nothing
end sub
sub session_onend
application.lock
application("online") = application("online")-1
application.unlock
end sub
</script>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>计数器例子</title>
</head>
<body>
<div align="center">您是本站第<font color="#FF0000"><%=application("counter")%></font>位贵宾！
</div>
</body>
</html>