title: Validation of a drop down list in PHP
body: <p>I'm trying to validate a form in PHP. I have instructions not to change the form itself (The names of the fields for example) and in it there is a drop down list with this:
      <code>&lt;option value=""&gt;&lt;/option&gt;</code></p>
  
  <p>I tried to validate with this :</p>
  
  <pre><code>if (!isset($_POST['cboproduit'])){
  $message.= "Vous devez sélectionner un téléphone &lt;br /&gt;";} 
  </code></pre>
  
  <p>but since there is a value with nothing in it, if I submit the form with the empty value it just saves an empty value.</p>
  
  <p>How can I do this in a simple way?</p>