打錯了節點的id了暈Uncaught TypeError: Cannot read property 'innerHTML' of null<script type="text/javascript">function getmore(){var p = document.getElementById("result").innerHTML;alert(p)var xhr = new XMLHttpRequest();xhr.open('GET', '{{url_for('api.get_posts')}}',true);xhr.onreadystatechange = function(){if(xhr.readyState ==4 && xhr.status == 200){  // alert('success');   document.getElementById("result").innerHTML = xhr.responseText;  var data = JSON.parse(xhr.responseText);     if(data){    console.log(xhr.responseText);     p = "fff";   }  else {    console.log('nothing');   } }else{  console.log('ajax error'); }}xhr.send();}</script>