急，表格单元是对象吗。

抛砖引玉:<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
</head><body>
<table width="80%" border="1" align="center" cellpadding="0" cellspacing="0">
  <tr> 
    <td id="aaa"><div align="center">aaa</div></td>
    <td id="bbb"><div align="center">bbb</div></td>
    <td id="ccc"><div align="center">ccc</div></td>
  </tr>
  <tr> 
    <td id="qqq"><div align="center">qqq</div></td>
    <td id="www"><div align="center">www</div></td>
    <td id="eee"><div align="center">eee</div></td>
  </tr>
  <tr> 
    <td id="zzz"><div align="center">zzz</div></td>
    <td id="xxx"><div align="center">xxx</div></td>
    <td id="ccc"><div align="center">ccc</div></td>
  </tr>
</table><form name="form1" method="post" action="">
  <input type="button" name="Submit" value="按钮" onClick="aaa.bgColor=990033">
  <input type="button" name="Submit" value="按钮" onClick="zzz.bgColor=990033">
</form>
<p>&nbsp;</p>
</body>
</html>