求助，哪位大佬看看

<!DOCTYPE html>
<html>
<head>
<title></title>
<style type="text/css">
table {
border: 1px solid #000;
width: 400px;
margin: 100px auto;
text-align: center;
}
td,
th {
border: 1px solid #333;
}
thead tr {
height: 40px;
background-color: #ccc
}
</style>
</head>
<body>
<table cellspacing="0">
<thead>
<tr>
<th>姓名</th>
<th>科目</th>
<th>科目</th>
<th>操作</th>
</tr>
</table>
<tbody>
</tbody>
</table>
<script type="text/javascript">
//先准备好学生的数据
var datas = [{
name:'张三',
subjec: 'JavaScropt',
score: 100
},{
name:'李四',
subjec: 'JavaScropt',
score: 35
},{
name:'王五',
subjec: 'JavaScropt',
score: 86
},{
name:'赵楼',
subjec: 'JavaScropt',
score: 50
}
];
//2往tbody里边创建行有多少人创建几行
var tbody = document.querySelector('tbody');
for (var i = 0; i < datas.length; i++) {
//1创建tr行
var tr = document.createElement('tr');
tbody.appendChild(tr);
//2行里边创建单元格td 单元格的舒亮亮决定于每个对象里的属性个数
for ( var k in datas[i]) {
//创建单元格
var td = document.createElement('td');
//把对象里边的属性给td
//console.log(datas[i][k])
td.innerHTML = datas[i][k];
tr.appendChild(td);
}
//3创建有删除两个字的单元格
var td = document.createElement('td');
td.innerHTml = '<a href ="javascript:;">删除</a>'
tr.appendChild(td);
}
//4删除操作开始
var as = documet.querySelectorAll('a');
for (var i = 0; i < as.length; i++) {
as[i].onclick = function(){
tbody.removeChild(this.parentNode.parentNode)
}
}
</script>
</body>
</html>
我是学了没多久，这个代码哪里出错了帮忙看一下谢了