/*
 * Dutch bank account numbers (not 'giro' numbers) have 9 digits
 * and pass the '11 check'.
 * We accept the notation with spaces, as that is common.
 * acceptable: 123456789 or 12 34 56 789
 */
$.validator.addMethod( "bankaccountNL", function( value, element ) {
	if ( this.optional( element ) ) {
		return true;
	}
	if ( !( /^[0-9]{9}|([0-9]{2} ){3}[0-9]{3}$/.test( value ) ) ) {
		return false;
	}

	// Now '11 check'
	var account = value.replace( / /g, "" ), // Remove spaces
		sum = 0,
		len = account.length,
		pos, factor, digit;
	for ( pos = 0; pos < len; pos++ ) {
		factor = len - pos;
		digit = account.substring( pos, pos + 1 );
		sum = sum + factor * digit;
	}
	return sum % 11 === 0;
}, "Please specify a valid bank account number." );
