我试图检测用户何时触摸了网页中的链接，何时触摸了页面的任何其他部分，但它不起作用-,在下面的代码中，无论我在哪里触摸，都会弹出警报“触摸了非链接”，而不管它是否是链接。
这个代码有什么问题？

function addListeners()
{  
    alert('adding listeners');

    // Attach the listener for touches on non-links to the document node
    document.addEventListener("touchstart", touchesOnNonLinksListerner, false);

    // Attach the listener for touches on links to the anchor nodes
    var links = document.getElementsByTagName("a");
    for (var index = 0; index < links.length; ++index)
    {
        links[index].addEventListener("touchstart", touchesOnNonLinksListerner, false);
    }
}; 

function touchesOnNonLinksListerner(event)
// Catches touches anywhere in the document
{
    alert("touched  a non link");
}

function touchesOnLinksListener(event)
// Listens for touches which occur on links, then prevents those touch events from bubbling up to trigger the touchesOnNonLinksListerner
{
    alert("touched a link");
    if (typeof event == "undefined")
    {
        event = window.event;
    }

    event.stopPropegation();
}