请问一下，这个JS效果怎么做的了？？？

Question

链接:
<a href="/bstd/xmsb.htm" target="_blank"><img onMouseOver="document.all['list1'].style.display=''" onMouseOut="document.all['list1'].style.display='none'" src='/images/bstd_button3.gif' border='0'></a>很简单,通过改变div的显示隐藏来做的呀~
//div
<DIV id=list1 onmouseover="document.all['list1'].style.display=''" style="DISPLAY: none; WIDTH: 100%; HEIGHT: 147px" onmouseout="document.all['list1'].style.display='none'"> 
<table width='439' border='0' cellpadding='0' cellspacing='0' background='images/td_d.gif' onmouseout="document.all['list1'].style.display='none'" height='147'><tr>
    <td align='center' valign='top'><br><br>
 <table width='90%' border='0' cellspacing='0'><tr> 
                              <td height='25'><img src='images/bstd_img.gif'></td>
                            </tr>
                            <tr>
                              <td height='10'></td>
                            </tr>
                          </table>
 <table width='90%' border='0'><tr>
    <td width='39%'><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/xmsb.htm"  class="blk">项目申报</a></td>
                              <td width='35%'><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/jzzj/index.htm" target="_blank"  class="blk">记者之家</a></td>
                              <td width='26%'><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="javascript:;" onmouseup="MM_openBrWindow('/bstd/gzwd.htm','ht','width=460,height=500,top=0,left=0,resizable=0,scrollbars=no,toolsbar=no')"  class="blk"   >公众问答</a></td>
  </tr>
  <tr>
                              <td><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/jdsprd.htm"  class="blk">科技基地审批及认定</a></td>
                                <td><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/zzrd.htm"  class="blk">资质认证</a></td>  
                                <td><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/kjjl.htm"  class="blk">科技奖励</a></td>
  </tr>
  <tr>
                                <td><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/kjhz.htm"  class="blk">国际科技合作</a></td>  
                                <td><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/xxjl.htm"  class="blk" >信息交流</a></td>  
                                <td><img src='images/dian4.gif' border='0'>&nbsp;&nbsp;<a href="/bstd/qt.htm"  class="blk">其它</a></td>
  </tr>
</table>
</td>
  </tr>
</table>
</div>

Answer 1

就是单元格的交互显示...<table>
<tr>
 <td onmouseover="document.all['tb1'].style.display='block'"
     onmouseout="document.all['tb1'].style.display='none'">办事通道</td>
 <td onmouseover="document.all['tb2'].style.display='block'"
     onmouseout="document.all['tb2'].style.display='none'">阅读通道</td>
</tr>
<tr id="tb1"  style="display:none">
 <td colspan="2">办事通道办事通道</td>
</tr>
<tr id="tb2" style="display:none">
 <td colspan="2">阅读通道阅读通道</td>
</tr>
</table>

Answer 2

<script language="JavaScript">
function show()
{
bt.style.display="none";
//bt.style.visibility="hidden";
}
function hidden()
{
bt.style.display="";
//bt.style.visibility="visible"
}
</script><input type="button" value="移到按钮/移出按钮" onmouseover="hidden()" onmouseout="show()">
<br><input type="button" name="bt" value="隐藏与显示"><span><font color="#009900">请观察这个span</font></span>

Answer 3

smallmaster(小和尚):你做的这种效果很好实现，但是当鼠标移出按钮的时候下面的按钮就没有了，就不能实现在下面的层上做连接文字的效果了不过还是谢谢各位