Как сделать?

<input id="pot-holder" type="button" value="Фон с подносиком">
<input id="coffee" type="button" value="Фон с кофе">

<script src="../lib/jquery-1.6.4.min.js"></script>
<script src="../jquery.backstretch.min.js"></script>
<script>
    $.backstretch("pot-holder.jpg", {speed: 500});
    
    $("#pot-holder").click(function() {
       $.backstretch("pot-holder.jpg");
    });
    
    $("#coffee").click(function() {
       $.backstretch("coffee.jpg");
    });
</script>

<div class="leftcol">                                  
                    <div class="block navi">
                      <div class="dbtm"> 
                          <h3 class="dtitle"><img src="{THEME}/images/spacer.gif" alt="Навигация" /></h3>
                        <div class="dcont">
                              <ul class="reset navilinks">                                  
                        <li><a href="/" title=""><span>Главная</span></a></li>
                                  <li><a href="#" title=""><span>Новости</span></a></li>
                                  <li><a href="#" title=""><span>Разное</span></a></li>                                                              
                                </ul>
                            </div>
                        </div>
                    </div>