如何在 JavaScript 中禁用右键单击上下文菜单

并不是说我试图阻止“查看源代码”或类似的东西，而是我正在为某些元素制作一些自定义上下文菜单。

编辑：对答案的回应：我试过这个：

<a id="moo" href=''> </a>

<script type="text/javascript">
    var moo = document.getElementById('moo');

    function handler(event) {
        event = event || window.event;

        if (event.stopPropagation)
            event.stopPropagation();

        event.cancelBubble = true;
        return false;
    }

    moo.innerHTML = 'right-click here';

    moo.onclick = handler;
    moo.onmousedown = handler;
    moo.onmouseup = handler;
</script>