file transfer - desparate desparate ?

I am using this code to have the user download a file I selected to his PC, 
generally a Windows PC:

print "Content-type: application/octest-stream\n";
print "Location: $DownloadFile\n\n";

I have tried using the content-disposition and changing the content type to 
everything I could think of -- I do not want the use to be able to open the 
file, just to download it!  How can I do this?

Major help and thanks!