延退怎么没消息了:如何避免此防盗链所连图片不提示下载？

<%
From_url = UCASE(Cstr(Request.ServerVariables("HTTP_REFERER")))
Serv_url = UCASE(Cstr(Request.ServerVariables("SERVER_NAME")))
if mid(From_url,8,len(Serv_url)) <> Serv_url then
response.write "非法链接！" '防止盗链
response.end
end if

Function GetFileName(longname)'/folder1/folder2/file.asp=>file.asp
while instr(longname,"/")
longname = right(longname,len(longname)-1)
wend
GetFileName = longname
End Function
Dim Stream
Dim Contents
Dim FileName
Dim TrueFileName
Dim FileExt
Const adTypeBinary = 1
FileName = Request.QueryString("FileName")
if FileName = "" Then
Response.Write "无效文件名！"
Response.End
End if
FileExt = Mid(FileName, InStrRev(FileName, ".") + 1)
select Case UCase(FileExt)
Case "ASP", "ASA", "ASPX", "ASAX", "MDB"
Response.Write "非法操作！"
Response.End
End select
Response.Clear
if lcase(right(FileName,3))="gif" or lcase(right(FileName,3))="jpg" or lcase(right(FileName,3))="png" then
Response.ContentType = "image/"&lcase(right(FileName,3)) '对图像文件不出现下载对话框
else
Response.ContentType = "application/ms-download"
end if
Response.AddHeader "content-disposition", "attachment; filename=" & GetFileName(Request.QueryString("FileName"))

Set Stream = server.createObject("ADODB.Stream")
Stream.Type = adTypeBinary
Stream.Open
if lcase(right(FileName,3))="pdf" then '设置pdf类型文件目录
TrueFileName = "/upfiles/"&FileName
end if
if lcase(right(FileName,3))="doc" then '设置DOC类型文件目录
TrueFileName = "/upfiles/"&FileName
end if
if lcase(right(FileName,3))="gif" or lcase(right(FileName,3))="jpg" or lcase(right(FileName,3))="png" then
TrueFileName = "/upfiles/"&FileName '设置图像文件目录
end if
Stream.LoadFromFile Server.MapPath(TrueFileName)
While Not Stream.EOS
Response.BinaryWrite Stream.Read(1024 * 64)
Wend
Stream.Close
Set Stream = Nothing
Response.Flush
Response.End
%>
这个防盗链可以起到防盗作用，但在站内用新窗口打开之后，并不是直接用浏览器显示，而是弹出下载对话框～～～我想要它直接显示，请问如何修改呢？？？谢谢！！！
另：“Response.AddHeader "content-disposition", "attachment; filename=" & GetFileName(Request.QueryString("FileName"))

把这句加到end if里面试试”
试过了，不行～～～