title: JQuery AJAX Post and Refresh Page Content without reload page
body: <p>Now I know that I am at risk here of asking a duplicate question, however I don't really know what to search for because I am a complete AJAX jQuery noob. Believe me, I have tried searching what I think is the obvious, with no luck so please go easy on me.</p>
  
  <p>I have a php wordpress site which shows prices in GBP as default. At the top, is a select box with <code>onchange="this.form.submit()"</code> which allows the user to change the default currency that all prices are quoted in.</p>
  
  <pre><code>&lt;form method="post" action=""&gt;
      &lt;select name="ChangeCurrency" onChange="this.form.submit()"&gt;
          &lt;option value="GBP"&gt;GBP&lt;/option&gt;
          &lt;option value="USD"&gt;USD&lt;/option&gt;
          &lt;option value="EUR"&gt;EUR&lt;/option&gt;
      &lt;/select&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>On the home page, are several, what I call <strong>"shortcode widgets"</strong>, each one containing products and price tables. A dashboard if you like. </p>
  
  <p>How it currently works (inefficient):</p>
  
  <ol>
  <li>User changes select.</li>
  <li>Form submitted</li>
  <li>Homepage reloaded with updated prices in selected currency.</li>
  </ol>
  
  <p>This is not good, because whenever somebody changes currency, the whole page is reloaded (this takes time, transfers approx 1mb without caching, not to mention unnecessary load on the server).</p>
  
  <p>What I want (more efficient):</p>
  
  <ol>
  <li>When the select box is changed, I wish to asynchronously post the form which changes the currency session variable.</li>
  <li>Each "shortcode widget" is updated one by one without having to reload the entire page.</li>
  </ol>
  
  <p>Is this something that jquery can do? where do I start?</p>
  
  <p>Just in case it makes any difference so that you can see what I mean, here is the URL so that you can see what I am talking about... <a href="http://bit.ly/10ChZys" rel="nofollow">http://bit.ly/10ChZys</a></p>
  
  <p><strong>PART 2:</strong>
  I have used jQuery and ajax to update the fixTable thanks to a mashup of answers below... I am using session variables to store the users choice, that way, if they return to the site, the option will be saved.</p>
  
  <p>I am having problems with my code because the session variable stored within <a href="http://goldealers.co.uk/wp-content/plugins/gd/tables.php?currency=GBP&amp;table=fixTable" rel="nofollow">http://goldealers.co.uk/wp-content/plugins/gd/tables.php?currency=GBP&amp;table=fixTable</a> appears to have a different session_id to the user's session id because the option is no longer stored.</p>
  
  <p>Is there a way of telling the server that they are one and the same session?</p>
  
  <p><strong>SOLUTION</strong>
  I used Ribot's Solution to start with which worked and solved the initial problem, then extended with NomikOS's solution...</p>