#city_selected{ width:200px; height:100px; position:absolute; display:none;}

<script type="text/javascript">
$("#change_city").click(function(){
    tipsWindown("切换城市", "text:"+function(){var txt = $("#city_selected").html(); return txt;}(), "250", "150", "true", "", "true", "id");
    // var num = $("#city_selected select");
    // alert(num);
    });
</script>

  <div id="city_selected">
   <table border="0" class="no_border">
      <tr>
        <td><select onchange="selectCity(this)"><option selected="selected">选择省份</option><option>江苏</option></select></td>
        <td><select onchange="selectCity(this)"><option selected="selected">选择市</option><option>苏州</option></select></select></td>
        <td><select onchange="selectCity(this)"><option selected="selected">选择市区</option><option>园区</option></select></select></td>
      </tr>
      <tr>
      </tr>
   </table>
   <div id="selected_city_result"></div>
    <script type="text/javascript">
          function selectCity(e){
               //alert($("#selected_city_result").html());
               $("#selected_city_result").html(e.value);
              }
    </script>
</div>

          function selectCity(e){
               $("#selected_city_result").html($(e).val());
              }

------解决方案--------------------
刚说错了  
你value根本就没值