#/usr/bin/perl -w
use strict;
use CGI;
my $q = new CGI;

print $q->header();
my $err = do_something();
print $err ? $err : "OK";

sub do_something { 
  if ( 1 + 1 == 2 ) {
     return 0;
  } else {
     return 'An error has occurred 1 + 1 is not equal to 2!'
  }
}