function switch_tab(tab_object) {
    var tab_object = tab_object;
    var content_object = document.getElementById(tab_object.id + "-content");
    var parent_object = document.getElementById(tab_object.parentNode.id);
    var tabs = parent_object.getElementsByTagName("li");
    for (var i = 0; i < tabs.length; i++) {
        var thisTab = tabs[i];
        if (thisTab.id) {
            var other_content_object = document.getElementById(thisTab.id + "-content");
            other_content_object.style.display = 'none';
            var other_tab_object = document.getElementById(thisTab.id);
            other_tab_object.className = null;
        }
    }
    tab_object.className = "selected";
    content_object.style.display = 'block';


    }