Select Active Item JS

active.js

var links = document.getElementsByClassName('link');
var choose = function() {
  for(var j=0; j < links.length; j++) {
    links[j].className = '';
  }
  this.className = 'active';
};
for(var i=0; i < links.length; i++) {
  links[i].addEventListener('click', choose, false);
}