ho trovato questo script:

<%
var fso = new ActiveXObject("Scripting.FileSystemObject");
var f=fso.getfile(Server.MapPath("\\immagini\\" + Request.QueryString("file_name")))
var strFileSize=f.size
var adTypeBinary=1
var objStream = new ActiveXObject("ADODB.Stream")
objStream.Open()
objStream.Type = adTypeBinary
objStream.LoadFromFile(Server.MapPath("\\immagini\ \"+ Request.QueryString("file_name")))
Response.AddHeader("Content-Disposition", "attachment; filename='\\immagini\\"+ Request.QueryString("file_name")+"'")
Response.AddHeader("Content-length",strFileSize)
Response.Charset = "UTF-8"
Response.ContentType = "text/html"
Response.BinaryWrite(objStream.Read)
Response.Flush
objStream.Close()
%>

utilizzandolo mi da l'errore alla riga 2, colonna 27:

"Prevista fine istruzione"