JavaScript to add MathJax support to Simplenote web app.

mathjax_simplenote.js

if (window.MathJax === undefined) {
    //Add the MathJax script
    var script = document.createElement("script");
    script.type = "text/javascript";
    script.src = "//cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML";
    var config = 'MathJax.Hub.Config({' + 'extensions: ["tex2jax.js"],' + 'tex2jax: { inlineMath: [["$","$"],["\\\\\\\\\\\\(","\\\\\\\\\\\\)"]], displayMath: [["$","$"],["\\\\[","\\\\]"]], processEscapes: true },' + 'jax: ["input/TeX","output/HTML-CSS"]' + '});';
    if (window.opera) {
        script.innerHTML = config
    } else {
        script.text = config
    }
    document.getElementsByTagName("head")[0].appendChild(script);

    //Add the reload tag
    script = document.createElement("script");
    script.text = 'document.getElementById("view_mode_markdown").onclick = ' + 'function() {MathJax.Hub.Queue(["Typeset", MathJax.Hub, "static_content"]);};';
    document.getElementsByTagName("head")[0].appendChild(script);
} else {
    //Render the content
    MathJax.Hub.Queue(["Typeset", MathJax.Hub, "static_content"]);
}

It looks great but I could not get it to work. Can you help please?

I use the console in the developer tools (Firefox) to work it.