asp高手帮忙看一下这段代码为何错误
下列代码,下载小文件正常(几十或几百 kb),但是下载8MB的文件,IE或其他下载软件已经提示是8MB的大小,但是下载到本地是0字节,不知为何错误 又该如何修正,感谢!!!

<%
FunctIon DownloadFIle(StrFIle) 
StrFIlename=StrFIle 
Response.Buffer=True 
Response.Clear 
Set S=Server.CreateObJect("ADODB.Stream") 
S.Open 
S.Type=1 
on Error Resume Next 
Set Fso=Server.CreateObJect("ScrIptIng.FIleSystemObJect") 
If Not Fso.FIleExists(StrFIleName) Then 
From_Url=Cstr(Request.ServerVarIables("HTTP_REFERER")) 
Serv_Url=Cstr(Request.ServerVarIables("SERVER_NAME")) 
If MId(From_Url,8,len(Serv_Url)) <> Serv_Url Then 
Response.WrIte "该文件不存在或者已经删除." 
Response.End 
End If 
Response.RedIrect Request.ServerVarIables("HTTP_REFERER") 
Response.End 
End If 
FileExt=MId(StrFIlename,InStrRev(StrFIleName, ".")+1) 
Select Case UCase(FIleExt) 
Case "ASP", "ASA", "ASPX", "ASAX", "MDB", "PHP", "JSP", "SHTML", "HTML", "HTM", "TV", "DATA" 
From_Url=Cstr(Request.ServerVarIables("HTTP_REFERER")) 
Serv_Url=Cstr(Request.ServerVarIables("SERVER_NAME")) 
If MId(From_Url,8,len(Serv_Url)) <> Serv_Url Then 
Response.WrIte "该文件不存在或者已经删除." 
Response.End 
End If 
Response.RedIrect Request.ServerVarIables("HTTP_REFERER") 
Response.End 
End Select 
Set F=Fso.GetFIle(StrFIlename) 
IntFIlelength=F.SIze 
s.LoadFromFIle(StrFIlename) 
If Err Then 
From_Url=Cstr(Request.ServerVarIables("HTTP_REFERER")) 
Serv_Url=Cstr(Request.ServerVarIables("SERVER_NAME")) 
If MId(From_Url,8,len(Serv_Url)) <> Serv_Url Then 
Response.WrIte "该文件数据不完整或许已损坏." 
Response.End 
End If 
Response.RedIrect Request.ServerVarIables("HTTP_REFERER") 
Response.End 
End If 
Set Upload=Server.CreateObJect("PersIts.Upload") 
If Upload Is Nothing Then 
Response.AddHeader "Content-DIsposItIon","attachment; FIlename="&F.Name 
Response.AddHeader "Content-Length",IntFilelength 
Response.CharSet="UTF-8" 
Response.ContentType="application/x-download" 
Response.BinaryWrite S.Read 
Response.Flush 
S.Close 
Set s=NothIng 
Else 
Upload.SendBinary StrFIlename,True,"application/x-download",False 
End If 
End FunctIon

call downloadFile("D:\www\soft\DownLoad\111.zip") 
 
%>

[解决办法]

call downloadFile("D:\www\soft\DownLoad\111.zip")
Sub downloadFile(file_url)
on error resume next
Dim Scs,ture_url,filename,exe_name,Range,file_name
ture_url=server.MapPath(file_url)
file_name=Mid(ture_url,instrRev(ture_url,"\")+1)
exe_name=Mid(file_name,instrRev(file_name,".")+1)'后缀名
filename=Mid(file_name,1,instrRev(file_name,".")-1)'文件名
Set Scs=CreateObject("Adodb.Stream")
Scs.Mode=3
Scs.Type=1
Scs.Open
Scs.LoadFromFile(ture_url)
If InStr("ASP,ASA,ASPX,ASAX,MDB,PHP,JSP,SHTML,HTML,HTM,TV,DATA",UCase(exe_name))>0 Then
Response.Write "禁止下载"
ElseIf Err.Number<>0 Then
Response.Write "下载出错"
Else
Response.ContentType="application/octet-stream"
If Instr(Request.ServerVariables("HTTP_USER_AGENT"),"MSIE")>0 Then filename=Server.URLEncode(filename)
Response.AddHeader "Content-Disposition:","Attachment;filename="&filename&"."&exe_name
Range=Mid(Request.ServerVariables("HTTP_RANGE"),7)
If Range="" Then
Response.BinaryWrite(Scs.Read)
Else
Scs.Postion=Clng(Split(Range,"-")(0))
Response.BinaryWrite(Scs.Read)
End If
End If
End Sub

[解决办法]
服务器有buffer限制，修改对应设置