jQuery实现简易聊天对话框

<!DOCTYPE html>
<html lang="en">
 
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style type="text/css">
    .talk_con {
      width: 600px;
      height: 500px;
      border: 1px solid #666;
      margin: 50px auto 0;
      background: #f9f9f9;
    }
 
    .talk_show {
      width: 580px;
      height: 420px;
      border: 1px solid #666;
      background: #fff;
      margin: 10px auto 0;
      overflow: auto;
    }
 
    .talk_input {
      width: 580px;
      margin: 10px auto 0;
    }
 
    .whotalk {
      width: 80px;
      height: 30px;
      float: left;
      outline: none;
    }
 
    .talk_word {
      width: 420px;
      height: 26px;
      padding: 0px;
      float: left;
      margin-left: 10px;
      outline: none;
      text-indent: 10px;
    }
 
    .talk_sub {
      width: 56px;
      height: 30px;
      float: left;
      margin-left: 10px;
    }
 
    .atalk {
      margin: 10px;
    }
 
    .atalk span {
      display: inline-block;
      background: #0181cc;
      border-radius: 10px;
      color: #fff;
      padding: 5px 10px;
    }
 
    .btalk {
      margin: 10px;
      text-align: right;
    }
 
    .btalk span {
      display: inline-block;
      background: #ef8201;
      border-radius: 10px;
      color: #fff;
      padding: 5px 10px;
    }
  </style>
  <script src='../js/jquery-1.12.4.js'></script>
  <script>
  $(function(){
    $('#talksub').click(function(){
      //发送单击，获取用户输入的数据value属性值
      var vals=$('#talkwords').val()
      //如果输入的数据为空，则弹窗提示
      if (vals=='')
      {
        alert('请输入数据！')
        return
      }
      //条件下拉列表中的value值是0还是1
      var whovals=$('#who').val()
      var str=""
      //选择A发送还是B发送
      if (whovals==0){
        str='<div class="atalk"><span>A：'+ vals+'</span></div>'
      }
      else{
        str='<div class="btalk"><span>B：'+ vals+'</span></div>'
      }
      //原有的内容+str,否则会覆盖掉原有内容
      $('#words').html($('#words').html()+str)
      //发送完数据后清空输入框
      $('#talkwords').val('')
    })
  })
  </script>
</head>
 
<body>
  <div class="talk_con">
    <div class="talk_show" id="words">
      <div class="atalk"><span>A：你还好吗？</span></div>
      <div class="btalk"><span>B：嗯，你呢？</span></div>
    </div>
    <div class="talk_input">
      <select class="whotalk" id="who">
        <option value="0">A：</option>
        <option value="1">B：</option>
      </select>
      <input type="text" class="talk_word" id="talkwords">
      <input type="button" value="发送" class="talk_sub" id="talksub">
    </div>
  </div>
</body>
 
</html>