".$_POST['zip']." "; if (preg_match("/^[1-9][0-9]{3}[\s]?[A-Za-z]{2}$/i", $_POST['zip'])) { echo "is een valide NL postcode."; echo "

"; echo ""; } else { echo "is geen valide NL postcode."; } } else { $html = "

"; $html .= "Postcode: "; $html .= ""; echo $html; } //echo "

"; //echo "The above output is generated by the code below:
"; //highlight_file( __FILE__ ); ?>