asp 点击链接 下载图片文件

<%
Dim Stream
Dim Contents
Dim FileName
Dim FileExt
Const adTypeBinary = 1
FileName = Request.QueryString("FileName")
if FileName = "" Then
    Response.Write "无效文件名."
    Response.End
End if
' 下面是不希望下载的文件
FileExt = Mid(FileName, InStrRev(FileName, ".") + 1)
Select Case UCase(FileExt)
    Case "ASP", "ASA", "ASPX", "ASAX", "MDB"
        Response.Write "受保护文件,不能下载."
        Response.End
End Select
' 下载这个文件
Response.Clear
Response.ContentType = "application/octet-stream"
Response.AddHeader "content-disposition", "attachment; filename=" & replace(lcase(filename),"../admin/main/upload/","")
Set Stream = server.CreateObject("ADODB.Stream")
Stream.Type = adTypeBinary
Stream.Open
Stream.LoadFromFile Server.MapPath(FileName)
While Not Stream.EOS
    Response.BinaryWrite Stream.Read(1024 * 64)
Wend
Stream.Close
Set Stream = Nothing
Response.Flush
Response.End
%>