Try adding if(defined $info) (and cleaning up the logic flow) like so:

if (defined($info) and (-e $info)) {
    unless ($query =~ /support/)) {
        print "<a href\=\"$webdir/cgi-bin/getprods.pl?$prodlisting\">"
+; 
        print "Product Listing</a><br><br>";
    }
    open (FILE, $info) or die "Can't open file!";
    print while <FILE>; 
    close FILE;
}
[download]

---

(Note you can do away with that while loop also like so:

{
           local $/ = undef;
           open (FILE, $info) or die "Can't open file!";
           print <FILE>;
           close FILE;
}
[download]

See perlvar for an explanation of $/.)

Makeshifts last the longest.