title: jQuery/js val() overwriting PHPs' $_POST['field']. How to fix?
body: <p>I've got a pretty complicated (for me!) form validation to do. I did all js and now I'm doing php stuff.</p>
  
  <p>The thing is I've put a possibility to copy part of the inputs to other, similar section (recipient -> payer). It's all done by jQuery first copying <code>$("input.payer_sth").val()</code> to <code>$("input.payer_sth")</code>, and then doing it again and again on keyup and blur.</p>
  
  <p>All my inputs are built like that:</p>
  
  <pre><code>&lt;input id="payer_name" name="payer_name" class="foo" type="text" value="&lt;?=$_POST['payer_name']?&gt;"/&gt;
  </code></pre>
  
  <p>as long as the ones that aren't modified by jQuery work all right on submit and "back", the ones that has modified <code>val()</code> are empty on back.</p>
  
  <p>What's obvious for me is that jQuery is overwriting <code>value="&lt;?=$_POST['field']?&gt;"</code> .</p>
  
  <p>How can this be fixed?</p>