var header = document.getElementsByClassName("custom-top-icons");
var icons = header[0].getElementsByClassName("content-icons");
for (var i = 0; i < icons.length; i++) {
icons[i].addEventListener("click", function() {
var current = document.getElementsByClassName("active");
current[0].className = current[0].className.replace(" active", "");
this.className += " active";
});
}