------------------------------------- <button id="toggleButton">Download</button> <script> function toggleDownloadParam() { var links = document.querySelectorAll('a[id="dld"]'); for (var i = 0; i < links.length; i++) { var link = links[i]; if (link.href.indexOf('?') === -1) { link.href += '?download=yes'; } else { link.href += '&download=yes'; } } } var toggleButton = document.getElementById('toggleButton'); toggleButton.addEventListener('click', function() { if (toggleButton.classList.contains('on')) { toggleButton.classList.remove('on'); toggleButton.textContent = 'Toggle'; toggleDownloadParam(); } else { toggleButton.classList.add('on'); toggleButton.textContent = 'Toggle (On)'; toggleDownloadParam(); } }); </script> <a href="example.html" id="dld">Download Link 1</a><br> </plaintext>