When writing CGI scripts it's always useful to use CGI. In your case something like the following may work.

use CGI qw(:standard);

#...your other code...

print img({src => "$courselocation/images/$value"});
[download]

$|=$_="1g2i1u1l2i4e2n0k",map{print"\7",chop;select$,,$,,$,,$_/7}m{..}g