1、有一个表格，当鼠标移动到某行时，该行变红，移除时，变为白色
<body>
<table border="1" width="300px">
<tr onmouseover="t1(0);" onmouseout="t2(0);">
<td>1</td>
<td>2</td>
<td>3</td>
</tr>
<tr onmouseover="t1(1);" onmouseout="t2(1);">
<td>1</td>
<td>2</td>
<td>3</td>
</tr>
<tr onmouseover="t1(2);" onmouseout="t2(2);">
<td>1</td>
<td>2</td>
<td>3</td>
</tr>
</table>
<script>
function t1(n){
var myTrs=document.getElementsByTagName("tr")[n];
//console.log(myTrs);
myTrs.style.backgroundColor="red";
}
function t2(n){
var myTrs=document.getElementsByTagName("tr")[n];
myTrs.style.backgroundColor="white";
}
</script>
</body>