Mọi người giúp code enter gửi ko load trang với

<script src="http://code.jquery.com/jquery-2.1.3.min.js"></script>
<div id="musicss"></div>
<script language="javascript" type="text/javascript">
 function playSound(soundfile) {
 document.getElementById("musicss").innerHTML=
 "<embed src=\""+soundfile+"\" hidden=\"true\" autostart=\"true\" loop=\"false\" width=\"1\" height=\"1\"  type=\"audio/mpeg\"/>";
 }
 </script>
<div class="shoutbox">
  <form action="#" method="post"> <span class="taochu"><textarea rows="3" cols="20" id="knoidung" style="width:auto" name="text"></textarea></span><br/> 
 <input type="button" value="Thêm tin nhắn" id="dangbai"/></form>
 
<script>$('textarea').on('keydown',function(event){if(event.keyCode==13)if(!event.shiftKey)$(this.form).submit()})</script>
 
  <span id="shoutbox">{{message_list}}</span>
{{paging_def}}
</div>
<script type="text/javascript">
$('#dangbai').click(function(){$.post("/main.php?id=ch_topic_h&uid=189256",{text: $(".taochu textarea").val()},function(data, status){$(".taochu textarea").val(null);});return false
});
 
function tailai(){$("#shoutbox").load("/main.php?f=3365610 #shoutbox");}
var xchay=setInterval("tailai()",1000);
</script>