Omzetten vakantiedagen [txtLabel_1] [txtLabel_2] [txtLabel_3] [txtLabel_4] [txtMandatory] [txtButton] [errorFillAllFields] [errorLegalHollidays] [errorFulltimeHours] [errorHoursWorked] [errorEmptyFulltimeHours] [errorDaysPerWeek] [txtResultTitle] [txtResultCopy]