#!d:\perl\bin\perl -w
use strict;
use CGI ':standard';

# usernames and passwords
my %login = (
  'antonis' => 'koukou',
  'giannis' => 'zabon'
);

sub login_form {
  my $msg = shift;

  print header,
    start_html('Login'),
      p(em($msg)),

      start_form( {method => 'post'} ),
        table(
          Tr(
            th('Username:'),
            td(
              textfield(
                {name => 'user', size => 20}
              )
            )
          ),
          Tr(
            th('Password:'),
            td(
              password_field(
                {name => 'pass', size => 20, force => 1}
              )
            )
          ),
          Tr(
            th( {colspan => 2}, submit('Login!') )
          )
        ),
      end_form,
    end_html;

  exit;
}


my ($user, $pass) = (
  param('user'), param('pass')
);

login_form('Please enter username/password to login:')
  unless (defined $user && defined $pass);

login_form('Invalid username or password. Please try again:')
  unless (exists($login{$user}) && $login{$user} eq $pass);

# Now logged in
print header,
  start_html('Welcome Back!'),
    p("Welcome back, $user!"),
  end_html;
  end_html;
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