css application: click on the table to change the color of the clicked row

The code is as follows:

<script> 
function bgChange(obj) 
{ 
    objobj.bgColor=obj.bgColor==""?"#B6DC73":""; 
} 
</script> 
<table width="80%" border="1" bgcolor="#ffffcc"> 
    <tr onclick="bgChange(this)"> 
        <td>aa25.cn</td> 
        <td>aa25.cn</td> 
    </tr> 
    <tr onclick="bgChange(this)"> 
        <td>aa25.cn</td> 
        <td>aa25.cn</td> 
    </tr> 
    <tr onclick="bgChange(this)"> 
        <td>aa25.cn</td> 
        <td>aa25.cn</td> 
    </tr> 
</table>