Edit in JSFiddle

MathJax.Hub.Config({
    extensions: ["mml2jax-bugfix.js"],
    menuSettings: {zoom:"Click"},
    "HTML-CSS": {scale:110},
    jax: ["input/MathML","output/HTML-CSS"]
});

if(location.href.split("#").length != 1) {
  MathJax.Hub.Register.StartupHook("End", function() {location.href = location.href; });
}

function updateModule(course)  {
    var query = "";
    query += "SELECT * ";
    query += "FROM xml ";
    query += "WHERE url='http://cnx.org/content/" + course + "/latest/body' ";
    //console.log("query=" + query);

    var yql = "";
    yql += "http://query.yahooapis.com/v1/public/yql?q=";
    yql += encodeURIComponent(query);
    yql += "&format=xml";
    yql += "&callback=?";
    //console.log("yql=" + yql);

    $.getJSON(yql,function(data) {
        //console.dir(data.results[0]);
        $course = $(data.results[0]);
        
        $("#xml").val(data.results[0]);
        $("#body").html(data.results[0]);
        $("img:not([src^='http'])").each(function(){
            $(this).attr("src","http://cnx.org/content/" + course + "/latest/" + $(this).attr("src"));
        });
    });
}

$("#module").change(function(){
    var course = $(this).val();
    updateModule(course);
});

updateModule($("#module option:first").val());

<h1>Select a ConneXions Module</h1>
<select id="module" name="module">
    <option value="m0050">The Sampling Theorem</option>
    <option value="m0051">Amplitude Quantization</option>
    <option value="m0052">Summary of Series and Parallel Combination Rules</option>
    <option value="m0053">Dependent Sources</option>
    <option value="m0054">Using Operational Amplifiers</option>
    <option value="m0055">Inverting Amplifier</option>
    <option value="m0056">Inverting Amplifiers with Impedances</option>
    <option value="m0057">Designing Circuits with Operational Amplifiers</option>
    <option value="m0058">Diode Behavior</option>
    <option value="m0059">Logarithmic Amplifier</option>
</select>

<br/><hr/><br/>

<h1>Body Content</h1>
<div id="body"></div>

<br/><hr/><br/>

<h1>Client Side XML Representation</h1>
<textarea id="xml" cols="70" rows="100"></textarea>