find words in html.js

/*
https://stackoverflow.com/questions/7380226/find-word-in-html
*/
function wrapWord(el, word)
{
    var expr = new RegExp(word, "i");
    var nodes = [].slice.call(el.childNodes, 0);
    for (var i = 0; i < nodes.length; i++)
    {
        var node = nodes[i];
        if (node.nodeType == 3) // textNode
        {
            var matches = node.nodeValue.match(expr);
            if (matches)
            {
                var parts = node.nodeValue.split(expr);
                for (var n = 0; n < parts.length; n++)
                {
                    if (n)
                    {
                        var span = el.insertBefore(document.createElement("span"), node);
                        span.appendChild(document.createTextNode(matches[n - 1]));
                    }
                    if (parts[n])
                    {
                        el.insertBefore(document.createTextNode(parts[n]), node);
                    }
                }
                el.removeChild(node);
            }
        }
        else
        {
            wrapWord(node, word);
        }
    }
}

var container = document.createElement("div");
container.style.display = "none";
document.body.appendChild(container);  // this step is optional
container.innerHTML = where;