title: Add text to hidden input value based on selection from dropdown
body: <p>Although this seems simple I am struggling to find a real solution. What I need to do is add/append text to the value of a hidden input based on the selection of a dropdown. The value in the dropdown will be added/appended to a randomly generated ID as a suffix that should look like this "12345678_myBrand". This is very easy to do, BUT I need the text (not the entire value) to change when the dropdown selection changes rather then simply adding/appending the most recently selected dropdown option.</p>
  
  <p>Here is what I'm doing</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;input id="myHiddenField" type="text"&gt;
  &lt;select id="brand"&gt;
      &lt;option value=""&gt;Please Select&lt;/option&gt;
      &lt;option value="First Choice"&gt;First Choice&lt;/option&gt;
      &lt;option value="Second Choice"&gt;Second Choice&lt;/option&gt;
      &lt;option value="Third Choice"&gt;Third Choice&lt;/option&gt;
      &lt;option value="Fourth Choice"&gt;Fourth Choice&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>jQuery:</p>
  
  <pre><code>jQuery(document).ready(function() {
      var brand = $('#brand');
      var hiddenField = $('#myHiddenField');
      hiddenField.val(1 + Math.floor(Math.random() * 10000000));
  
      brand.change(function() {
  
          hiddenField.val( hiddenField.val() + "_" + brand.val() );
  
      });
  });
  </code></pre>
  
  <p><a href="https://jsfiddle.net/wo6a5nkf/2/" rel="nofollow">https://jsfiddle.net/wo6a5nkf/2/</a></p>
  
  <p>Obviously I don't want to keep adding/appending the suffix to the id so how do I simply change the text without adding/appending every single option selected???</p>