Create Globally Unique ID in JavaScript
<p>I have a script that, when a user loads, creates a unique id. Which is then saved in <code>localStorage</code> and used for tracking transactions. Sort of like using a cookie, except since the browser is generating the unique id there might be collisions when sent to the server. Right now I'm using the following code:</p>

<pre class="lang-js prettyprint-override"><code>function genID() {
    return Math.random().toString(36).substr(2)
        + Math.random().toString(36).substr(2)
        + Math.random().toString(36).substr(2)
        + Math.random().toString(36).substr(2);
}
</code></pre>

<p>I realize this is a super basic implementation, and want some feedback on better ways to create a "more random" id that will prevent collisions on the server. Any ideas?</p>
