document.addEventListener('DOMContentLoaded', function() { var couplerSelect = document.getElementById('coupler'); var fiberSelect = document.getElementById('fiber'); function toggleFiberSelection() { if (couplerSelect.value === 'Yes') { fiberSelect.removeAttribute('disabled'); } else { fiberSelect.setAttribute('disabled', 'true'); fiberSelect.value = ''; // Setzt den Wert zurück } } toggleFiberSelection(); // Initiale Prüfung couplerSelect.addEventListener('change', toggleFiberSelection); // Event Listener });