function getElementByClass(element, className) {
    tc = element.childNodes;
    for (var i = 0; i < tc.length; i++) {
        if (tc[i].className == className) { return tc[i]; }
    }
    return null;
}

function toggle(target, event) {
    exdiv = getElementByClass(target, "example");
    excdiv = getElementByClass(exdiv, "example-contents");
    titlediv = getElementByClass(exdiv, "title");

    if (!titlediv || !titlediv.contains(event.target)) {
        return;
    }

    if (excdiv.style.display != 'block') {
        excdiv.style.display = 'block';
    } else {
        excdiv.style.display = 'none';
    }
}