var quater = document.getElementsByClassName("team-pic"); var triangle_team = document.getElementsByClassName("point")[0].getElementsByClassName("quater"); var team_description = document.getElementsByClassName("single-team"); var active_triangle = triangle_team[0]; var active_description = team_description[0]; function addListTeam() { for (var i = 0; i < quater.length; i++) { quater[i].setAttribute("data", i); quater[i].addEventListener("click", change_member); } } function change_member(e) { var value = this.getAttribute("data"); active_triangle.classList.remove("active"); active_description.classList.remove("active"); active_triangle = triangle_team[value]; active_description = team_description[value]; active_triangle.classList.add("active"); active_description.classList.add("active"); } addListTeam();