Jeg fandt flg dokumentation på Nettet
lngFileNum = FreeFile
Open strFileName For Binary As lngFileNum
lngFileSize = LOF(lngFileNum)
ReDim bytFileContent(lngFileSize)
Get lngFileNum, 1, bytFileContent
Close lngFileNum
strDownloadFileName = Right$(strFileName, Len(strFileName) - InStrRev(strFileName, \"\\\"))
Response.Buffer = True
Response.ContentType = \"application/octet-stream\"
Response.AddHeader \"Content-Disposition\", \"attachment; FileName = \" & _
strDownloadFileName
Response.AddHeader \"Content-Length\", lngFileSize
Response.AddHeader \"Document\", strDownloadFileName
Response.AddHeader \"Script_Name\", strDownloadFileName
Response.BinaryWrite bytFileContent
http://www.aspwatch.com/c/200037/d712E66F68B7A11D4AEF700A0C9E95208.asp