title: Javascript alert if value is empty and delete confirmation if it isn't
body: <p>I have a form that deletes a a value once the user has confirmed the action via a javascript confirm.  This works well but I would also like the script to alert the user if the value was empty therefore stopping the script from running altogether.</p>
  
  <pre><code>&lt;script&gt;
      function delete_confirm() {
          var msg = confirm('Are you sure you want to delete the selected audit');
          if (msg == false) {
              return false;
          }
      }
  &lt;/script&gt;
  
  
  &lt;form id="audit_control_form" method="post" 
      action="&lt;?php echo $_SERVER['PHP_SELF']; ?&gt;"&gt;
      &lt;select id="audit_id_select" name="audit_id_select" style="width:150px"&gt;
          &lt;option value=""&gt;Please select&lt;/option&gt;
          &lt;? while ($row = mysqli_fetch_assoc($result)) {
              if ($row['dateEnd'] == '0000-00-00') {
                  $dateEnd = 'Present';
              } else {
                  $dateEnd = date('d-m-Y', strtotime($row['dateEnd']));
              }
              echo '&lt;option value="'.$row['auditID'].'"&gt;'.$row['auditName']
                  .' (' . date('d-m-Y', strtotime($row['dateStart'])) 
                  .' - '.$dateEnd . ')&lt;/option&gt;';
          } ?&gt;
      &lt;/select&gt;
      &lt;input type="submit" name="audit_delete_submit" 
          onClick="return delete_confirm()" value="Delete" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I am not sure what is the best way to implement this (I'm fairly new to javascript).</p>