js创建表格和删除表格中的行
    <script>
	// 为表增加一行
	function create()
	{
	  var tableObj = document.getElementById("tab"); 	
	  alert(tableObj.rows.length);
	  var newRowObj = tableObj.insertRow(tableObj.rows.length);	  
	  // 此处的顺序应该和下面的顺序一致
	  var newColName = newRowObj.insertCell(newRowObj.cells.length);
	  var newColGender = newRowObj.insertCell(newRowObj.cells.length);
		var newColAge = newRowObj.insertCell(newRowObj.cells.length);
		var newColButton=newRowObj.insertCell(newRowObj.cells.length);		
		newColName.innerHTML = '刘德华';
	  newColGender.innerHTML = '男';
	  newColAge.innerHTML = 46;
	  newColButton.innerHTML = '<input type="button" value="Delete" onclick="deleteCurrentRow(this)">';
	}	
	// 删除一行
	function deleteCurrentRow(obj)
	{
	  var trObj = obj.parentNode.parentNode;
	  var tBody = trObj.parentNode;
	  tBody.removeChild(trObj);
	}		
</script>
<html>
	<body>
		<center>
			<input type="button" value="create table" onclick="create()"
			<div id="table"></div>
			<div>
			  <table id="tab">
			    <tr>
			        <td>姓名</td>
			        <td>性别</td>
			        <td>年龄</td>
			        <td>操作</td>
			    </tr>
			  </table>	
			</div>
	</center>
	</body>
</html>