#!/bin/sh
echo content-type: text/plain
echo
date

##</code><code>##

#!/your/path/to/perl
print "Content-type: text/plain\n\n";
print "Hello world at " . localtime() . "\n";

##</code><code>##

#!/your/path/to/perl
BEGIN { print "Content-type: text/plain\n\n--OUTPUT--\n"; }
... rest of your script ...

##</code><code>##

BEGIN {
  print "Content-type: text/plain\n\n--OUTPUT--\n";
  open STDERR, ">&STDOUT"; # errors go to browser now
}
... rest of your script ...