my $foo = CalcFoo( { bar => 'abc', baz => 'def' } );

sub CalcFoo
{
  my $href = $_[0];

  my $foo;
  if ( defined $href->{bar} and defined $href->{baz} )
  {
    $foo = $href->{bar} . $href->{baz};
  }
  else
  {
    print "Error: pls define bar and baz\n";
  }
  return $foo;
}

##</code><code>##

$line = padded({text=>$line, cols=>20..21, centered=>1, filler=>$SPACE});

##</code><code>##

Odd number of elements in anonymous hash at demo.pl line 42

##</code><code>##

$line = padded(text=>$line, cols=>20..21, centered=>1, filler=>$SPACE);