The nextSibling property of DOM nodes works perfectly in all browsers and does exactly what you'd expect. If there is no next sibling, it returns null.

Iterating over a NodeList (which is what getElementsByTagName returns) is identical to iterating over an array using a standard for loop. The following will iterate over the links and alert each time it finds one whose next sibling is a <div>:

var menu = document.getElementById('menu');

var links = menu.getElementsByTagName('a');



// Iterate over the links

for (var i = 0, len = links.length, link; i < len; ++i) {

    link = links[i];

    if (link.nextSibling && link.nextSibling.nodeName == DIV) {

        alert(Next sibling is DIV!  + link.innerHTML);

    }

}

Note that in non-IE browsers, whitespace between elements in HTML is considered a text node. You may want to ignore these whitespace nodes when considering what the next sibling of each link is. The following will do that:

function isWhitespace(node) {

    return node.nodeType == 3 && /^s*$/.test(node.data);

}



// Iterate over the links

for (var i = 0, len = links.length, link, next; i < len; ++i) {

    link = links[i];

    next = link.nextSibling;

    if (next && isWhitespace(next)) {

        next = next.nextSibling;

    }

    if (next && next.nodeName == DIV) {

        alert(Next sibling is DIV!  + link.innerHTML);

    }

}