编程练习
制作一个表格，显示班级的学生信息。
要求：
1. 鼠标移到不同行上时背景色改为色值为 #f2f2f2，移开鼠标时则恢复为原背景色 #fff
2. 点击添加按钮，能动态在最后添加一行
3. 点击删除按钮，则删除当前行
<!DOCTYPE html> <html> <head> <title> new document </title> <meta http-equiv="Content-Type" content="text/html; charset=gbk"/> <script type="text/javascript"> window.onload = function(){ Highlight(); } function addOne(obj){ var tbody = document.getElementById('table').lastChild; var tr = document.createElement('tr'); var td = document.createElement("td"); td.innerHTML = "<input type='text'/>"; tr.appendChild(td); td = document.createElement("td"); td.innerHTML = "<input type='text'/>"; tr.appendChild(td); td = document.createElement("td"); td.innerHTML = "<a href='javascript:;' onclick='deleteRow(this)'>删除</a>"; tr.appendChild(td); tbody.appendChild(tr); Highlight(); } function deleteRow(obj){ var tbody = document.getElementById('table').lastChild; var tr = obj.parentNode.parentNode; tbody.removeChild(tr); } function Highlight(){ var tbody = document.getElementById('table').lastChild; trs = tbody.getElementsByTagName('tr'); for(var i =1;i<trs.length;i++){ trs[i].onmouseover = function(){ this.style.backgroundColor ="#f2f2f2"; } trs[i].onmouseout = function(){ this.style.backgroundColor ="#fff"; } } } </script> </head> <body> <table border="1" width="50%" id="table"> <tr> <th>学号</th> <th>姓名</th> <th>操作</th> </tr> <tr> <td>xh001</td> <td>王小明</td> <td><a href="javascript:;" onclick="deleteRow(this)">删除</a></td> </tr> <tr> <td>xh002</td> <td>刘小芳</td> <td><a href="javascript:;" onclick="deleteRow(this)">删除</a></td> </tr> </table> <input type="button" value="添加一行" onclick="addOne()" /> </body> </html>