Javascript Regex to replace text NOT in html attributes

walk.js

walk(document.body);
setTimeout(function() {
    walk(document.body);
}, 1000);

function walk(node)
{
    // Source: http://is.gd/mwZp7E

    var child, next;

    switch ( node.nodeType )
    {
        case 1:  // Element
        case 9:  // Document
        case 11: // Document fragment
            child = node.firstChild;
            while ( child )
            {
                next = child.nextSibling;
                walk(child);
                child = next;
            }
            break;
        case 3: // Text node
            handleText(node);
            //imgFind(node);
            break;
    }
}