关于Microsoft VBScript 运行时错误 错误 '800a000d'的问题

Microsoft VBScript 运行时错误 错误 '800a000d'

类型不匹配: '[string: ""]'

/counter.asp，行 12

 

<%
dim visitors,whichfile,thisfile,fs,out
whichfile=server.mappath("functions/counter.txt")

set fs=createobject("Scripting.FileSystemObject")
set thisfile=fs.opentextfile(whichfile)
visitors=thisfile.readline
thisfile.close

if session("in")<>"in" then
session("in")="in"
visitors=visitors+1
end if

response.write visitors

set out=fs.createtextfile(whichfile)
out.writeLine(visitors)
out.close

set fs=nothing
%>

 

 

请高手解答