function summer_camp_openCity(evt, cityName) {
    var summer_camp_i, summer_camp_tabcontent, summer_camp_tablinks;
    summer_camp_tabcontent = document.getElementsByClassName("tabcontent");
    for (summer_camp_i = 0; summer_camp_i < summer_camp_tabcontent.length; summer_camp_i++) {
        summer_camp_tabcontent[summer_camp_i].style.display = "none";
    }
    summer_camp_tablinks = document.getElementsByClassName("tablinks");
    for (summer_camp_i = 0; summer_camp_i < summer_camp_tablinks.length; summer_camp_i++) {
        summer_camp_tablinks[summer_camp_i].className = summer_camp_tablinks[summer_camp_i].className.replace(" active", "");
    }
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}