var acc = document.getElementsByClassName("accordion"); var i; for (i = 0; i < acc.length; i++) { acc[i].addEventListener("click", function() { /* Toggle between adding and removing the "active" class, to highlight the button that controls the panel */ this.classList.toggle("active"); /* Toggle between hiding and showing the active panel */ var panel = this.nextElementSibling; if (panel.style.display === "block") { panel.style.display = "none"; } else { panel.style.display = "block"; } }); }