Cần giúp đỡ về show product php jquery

bạn muốn xài form thì fải có nút submit <input> nữa

còn để khơi khơi chỉ có 2 cái <select> thì fải dùng ajax

thì đó nên mới nhờ anh em giúp ~~! viết hoài ko ra nè Ajax hoac jquery giup minh với mình newbie

Website no nè: thevillage.tk/menu.php

Hnay mới viet them cai nay @@

HTML:

<div class="content"><div class="ic">More Website Templates in NeV3RmI's Website</div>
  <div class="container_12">
    <div class="grid_6">
      <h2>Our Menu</h2>
      <p class="col2 inn1"><a href="#">Integer non metus justo ac posuere turpis. Integer iaculis porta metus, in aliquam orci vehicula sit amet. Suspendisse turpis mauris, laoreet ac aliquet a lobortis in massa. Etiam tortor metus, tincidunt vel congue etu</a></p>
      <p>Aenean sed nunc lorem, nec ornare nibh. Pellentesque vitae sem odio. Vivamus vulputate est eget elit rutrum a consectetur justo aliquet. Aliquam hendrerit consectetur mi, non molestie massa venenatis quis. Integer aliquet euismod nisl, et sagittis sem scelerisque sit amet. Etiam dapibus, tellus et imperdiet pulvinar, urna nunc consectetur enim, in </p>
      <div class="menu">
        <div class="grid_3 alpha">
          <img src="images/page3_img1.jpg" alt="" class="img_inner">
          <h3><a href="#">Donec</a></h3>
       
          <img src="images/page3_img3.jpg" alt="" class="img_inner">
          <h3><a href="#">Holity as Polfh</a></h3>
       
          <img src="images/page3_img5.jpg" alt="" class="img_inner">
          <h3 class="mb0"><a href="#">Gyloit</a></h3>
         
          <p style="height:5px">&nbsp;</p>
           <?php echo $dynamicList0 ?>
        </div>
       
        <div class="grid_3 omega">
          <img src="images/page3_img2.jpg" alt="" class="img_inner">
          <h3><a href="#">Murtyio</a></h3>
       
          <img src="images/page3_img4.jpg" alt="" class="img_inner">
          <h3><a href="#">Kiperty</a></h3>
       
          <img src="images/page3_img6.jpg" alt="" class="img_inner">
          <h3 class="mb0"><a href="#">Liotymer</a></h3>
          <p style="height:5px">&nbsp;</p>
           <?php echo $dynamicList1 ?>
         
        </div>
        <div id="testshow"></div>
       
      </div>
      <div class="clear"></div>
    </div>
   
    <div class="grid_5 prefix_1">
    <div id="theFixed" style="position:fixed;">
      <script>
    var windw = this;

$.fn.followTo = function ( pos ) {
    var $this = this,
        $window = $(windw);
   
    $window.scroll(function(e){
        if ($window.scrollTop() > pos) {
            $this.css({
                position: 'absolute',
                top: pos
            });
        } else {
            $this.css({
                position: 'fixed',
                top: 175
            });
        }
    });
};

$('#theFixed').followTo(<?php echo $calculate ?>);
</script>
<div style="display:inline-block; margin:auto;">



        <!-- Select List --> 
         
         
         
          <script>
 $(document).ready(function() {
              $('#category').onchange(function(){
            $.post('productshow.php', { category: productshow.category.value},
            function(result) {
                $('#testshow').html(result).show();
            });
        });
    });
</script>
          <form id="productshow" method="post">
          <select name="category" id="category">
         <option value="All" selected="selected">All Category</option>
          <option value="Opt1">Opt1</option>
          <option value="Opt2">Opt2</option>
          <option value="Opt3">Opt3</option>
          </select>
         
          <select name="subcategory" id="subcategory">
          <option value="All" selected="selected">All Subcategory</option>
          <option value="SubOpt1">SubOpt1</option>
          <option value="SubOpt2">SubOpt2</option>
          <option value="SubOpt3">SubOpt3</option> 
          </select>
          </form>
          <!-- End of Select List -->
</div>