动态改变td表格的样式(改变背景图片,td边框,td背景颜色)

<table width="900" border="1" align="center" cellpadding="0" cellspacing="0" bordercolor="#FFFFFF">
<style >
.td1
{
background-image:url(../images/bg_orgbuttononbackground_1x.gif);
background-color:#FCBA8F;
border:1px solid #F7833C;
font-weight:bold;
color:#ffffff;
}
.td2
{
background-image:url(../images/bg_buttonbackground_1x21.gif);
background-color:#EDEDEE;
border:1px solid #CCCBCB;
}
</style>
<tr>
<td width="100" height="26" class="td1" id="t1" style="cursor:hand;" onclick="this.className='td1';t2.className='td2';t3.className='td2';" >
             <div align="center">详细信息</div>
             </td>
<td width="10"><div align="center"></div></td>
<td width="100" height="26" class="td2" id="t2" style="cursor:hand;" onclick="this.className='td1';t1.className='td2';t3.className='td2';">
             <div align="center">公司介绍</div>
             </td>
<td width="10"><div align="center"></div></td>
<td width="100" height="26" class="td2" id="t3" style="cursor:hand;" onclick="this.className='td1';t1.className='td2';t2.className='td2';">
             <div align="center">联系方式</div>
             </td>
<td width="10"><div align="center"></div></td>
<td width="100"><div align="center"></div></td>
<td><div align="center"></div> <div align="center"></div></td>
</tr>
<tr>
<td height="4" colspan="8" bordercolor="#F16419" bgcolor="#F16419"></td>
</tr>
</table>