Load billede med script

Dette script virker fint i IE og firefox.
Men kan det anbefales at bruge for at sikre sine data på bagsiden af wwwroot og vil det virke i alle browser?
Ligeledes cachecontrol?

<%
Response.Buffer = true
Response.CacheControl = "no-cache"
Response.Expires = -1

if session("brugernavn") = "" then
response.redirect ("404.asp")
end if

Const adTypeBinary = 1

Response.Expires = 0
Response.Buffer = TRUE

file = request.querystring("id")

Set uAgent = Request.ServerVariables("HTTP_USER_AGENT")
if (inStr(uAgent, "IE")) Then
'Explorer
Response.ContentType = "m_type"
Response.AddHeader "Content-Disposition", "atachment; filename="& file
Else
'NetScape
Response.ContentType = "image/JPEG"
'Response.AddHeader "Content-Disposition", "attachment; filename="& chr(34) & file & chr(34)
End if

Dim objStream
Set objStream = Server.CreateObjekt("ADODB.Stream")

objStream.Type = adTypeBinary
objStream.LoadFromFile server.mappath("minedata/" & file & "")
Response.BinaryWrite objStream.Read

objStream.Close
Set objStream = Nothing

Response.Flush
%>