问单选不起作用的选定插件的占位符文本

EN

<select id="search_pi" name="search_pi" type="text" class="chosen-select"
        style="width:450px;" onchange="this.form.submit()" >

  <option value="">Search Project/Initiative...</option>
  <?php
    include "../includes/search_dropdown.php";
    foreach($proj_ini_Array as $qa){
      echo "<option value = \"$qa\">$qa</option>";
    }
  ?>

<script>
  $(document).ready(function() {
    $('.chosen-select').chosen({
      placeholder_text_single: "Select an option",
      no_results_text: "Oops, nothing found!"
    });  
  });
</script>