## warn if we get an abnormal exit status
system ("sed -e 's[$c][$b]g' $File1 > $Replace_html")
 == 0 or warn "sed had problems (exit val $?)\n";

##</code><code>##

(my $search  = $c) =~ s[/](\\/)g;
(my $replace = $b) =~ s[/](\\/)g;
system("sed -e 's/$search/$replace/g' $File1 > $Replace_html")
  == 0 warn "sed had problems (exit val $?)\n";