如何实现:鼠标移动到表格上时，该行高亮显示？请指点一二

<table border="1" width="100" cellspacing="0" cellpadding="0">
  <tr onmouseover="bgColor='#3366cc'" onmouseout="bgColor='#ffffff'">
    <td width="100%">　</td>
  </tr>
  <tr onmouseover="bgColor='#3366cc'" onmouseout="bgColor='#ffffff'">
    <td width="100%">　</td>
  </tr>
  <tr onmouseover="bgColor='#3366cc'" onmouseout="bgColor='#ffffff'">
    <td width="100%">　</td>
  </tr>
  <tr onmouseover="bgColor='#3366cc'" onmouseout="bgColor='#ffffff'">
    <td width="100%">　</td>
  </tr>
</table>