PHP+Mysql+Ajax实现淘宝客服或阿里旺旺聊天功能(前台页面)

<script>
 $(".tc").click(function(){
  $("#kuangjia").show();  
 })
  $(".fasong").click(function(){
  var nr=$("#words").val();
  $.ajax({
   url:"qt-speak-cl.php",
   data:{words:nr},
   type:"POST",
   dataType:"TEXT",
   success: function(data){
    if(data==1)
    {
    window.location.href="qt-dh.php" rel="external nofollow" rel="external nofollow" ; 
    }
    else{
     alert("发送内容不能为空！");
    }
    }
  })
 }) 
  $("#dh").click(function(){
  $.ajax({
   url:"qt-yidu-cl.php",
   dataType:"TEXT",
   success: function(data){
//    alert(data);     
    window.location.href="qt-dh.php" rel="external nofollow" rel="external nofollow" ;    
   }   
  })
 })
</script> 

<?php
session_start();
require "DBDA.class.php";
$db = new DBDA(); 
$uid = $_SESSION["uid"];
$words =$_POST["words"];
$chtime=date("Y-m-d H:i:s",time());
$jieshou = "zhangsan";
if(!empty($words))
{
$sql="insert into duihua values ('','{$jieshou}','{$uid}','','{$words}',0,'{$chtime}')";
echo $db->query($sql,0);
<em id="__mceDel">}
else
{ 
 echo "发送内容不能为空！";
}
?>
</em>