原生JavaScript实现简易留言板

<script>

 window.onload = function(){
 
 var oMessageBox = document.getElementById("messageBox");
 var oInput = document.getElementById("myInput");
 var oPostBtn = document.getElementById("doPost");
 
 oPostBtn.onclick = function(){
  if(oInput.value){
  //写入发表留言的时间
  var oTime = document.createElement("div");
  oTime.className = "time";
  var myDate = new Date();
  oTime.innerHTML = myDate.toLocaleString();
  oMessageBox.appendChild(oTime);
  
  //写入留言内容
  var oMessageContent = document.createElement("div");
  oMessageContent.className = "message_content";
  oMessageContent.innerHTML = oInput.value;
  oInput.value = "";
  oMessageBox.appendChild(oMessageContent);
  }
  
 }
 
 }

</script>

<body>
 <div class="content">
    <div class="title">用户留言</div>
    <div class="message_box" id="messageBox"></div>
    <div><input id="myInput" type="text" placeholder="请输入留言类容"><button id="doPost">提交</button></div>
  </div>
</body>