怎样在javascript让每一个表格都让一个数组元素代表

var table_tag=document.getElementsByTagName("table");
这样就可以了
getElementsByTagName("xxx")会提取到所有tagname也就是标签为XXX的元素集合

<style>
.onhover{ background-color:#006699}
.onout{ background-color:#FF0000}
</style>
<TABLE id="senfe" cellSpacing=0 cellPadding=0 width="650px"
border=0>
<TBODY>
<TR>
<TD> sdsassasssassasa</td>
</tr>
<TR>
<TD> sdsassasssassasa</td>
</tr>
</TBODY>
</TABLE>

<script>
var t=document.getElementById("senfe")
for(i=0;i<t.rows.length;i++)
{
t.rows[i].onmouseover=function(){this.className='onhover'}
t.rows[i].onmouseout=function(){this.className='onout'}
}
</script>

var table_tag=document.getElementsByTagNam