Looping through XML with jQuery

I've got some basic code that can loop through some XML that's generated from Adobe RoboHelp (for our help documentation). This works fine, but since a topic could be nested as many time as the writer wants, i need a better way to loop through this XML rather than just nesting .each() loops.

Here's what the XML looks like

<?xml version="1.0" encoding="utf-8"?>
<!--RoboML: Table of Content-->
<roboml_toc>
  <page title="Welcome" url="Welcome.htm"/>
 <book title="Getting Started" url="Getting_Started/Initial_Setup.htm">
   <page title="Initial Setup" url="Getting_Started/Initial_Setup.htm"/>
   <page title="Customize Settings" url="Getting_Started/Settings.htm"/>
 </book>
 <book title="Administrator Services" url="Administrator_Services/General_Administrator.htm">
  <book title="Portal Workspace" url="Administrator_Services/Portal_Workspace/AdminHome.htm">
    <page title="Home" url="Administrator_Services/Portal_Workspace/AdminHome.htm"/>
    <page title="Portal Accounts" url="Administrator_Services/Portal_Workspace/Portal_Accounts.htm"/>

  </book>
  <book title="SpamLab" url="Administrator_Services/SpamLab/SpamLab_Admin_General.htm">
    <page title="Alerts" url="Administrator_Services/SpamLab/Alerts.htm"/>
    <page title="Spam Quarantine" url="Administrator_Services/SpamLab/Admin_Spam_Quarantine_.htm"/>

  </book>

 </book>
 <book title="User Services" url="User_Services/General_User.htm">
  <book title="Portal Workspace" url="User_Services/Portal_Workspace/Home.htm">
    <page title="Home" url="User_Services/Portal_Workspace/Home.htm"/>
    <page title="Self Help" url="User_Services/Portal_Workspace/Self_Help.htm"/>
  </book>
  <book title="SpamLab" url="User_Services/SpamLab/SpamLab_General.htm">
    <page title="Spam Quarantine" url="User_Services/SpamLab/Spam_Quarantine.htm"/>
    <page title="Virus Quarantine" url="User_Services/SpamLab/Virus_Quarantine.htm"/>
  </book>

  <book title="Encryption" url="User_Services/Encryption/Encryption_General.htm">
    <page title="Outlook Plug-in" url="User_Services/Encryption/Encryption_Outlook_Plug_in.htm"/>
  </book>
 </book>
</roboml_toc>

A <page> is an article, and a <book> is a folder.

Her's my jQuery code, which only can look one level deep of tags

   //Get the TOC
$tocOutput="";
$.get(tocURL,function(toc){
    $(toc).children().each(function(){
        $tocOutput+="<li><a href='"+$(this).attr("url")+"'>"+$(this).attr("title")+"</a>";
        if(this.tagName=="BOOK"){
            $tocOutput+="<ul>";
            $(this).find("page").each(function(){
                $tocOutput+="<li><a href='"+$(this).attr("url")+"'>"+$(this).attr("title")+"</a></li>";
            });
            $tocOutput+="</ul>";
        }
        $tocOutput+="</li>";
    });
    $("#list").html($tocOutput);

I know there's a better way to just loop through all elements and then determine if the element has children, etc. but I just can't think of how to do it.

Any help is greatly appreciated!

Recursive functions work well for this. When you create a function that creates and uses an internal recursive closure you can wrap it all up in a neat little package:

    $.get(tocURL, function(toc) {
    function makeToc($xml) {
        // variable to accumulate markup
        var markup = "";
        // worker function local to makeToc
        function processXml() {
            markup += "<li><a href='" + $(this).attr("url") + "'>" + $(this).attr("title") + "</a>";
            if (this.nodeName == "BOOK") {
                markup += "<ul>";
                // recurse on book children
                $(this).find("page").each(processXml);
                markup += "</ul>";
            }
            markup += "</li>";
        }
        // call worker function on all children
        $xml.children().each(processXml);
        return markup;
    }
    var tocOutput = makeToc($(toc));
    $("#list").html(tocOutput);
});