请问怎样把网页分成4个小框?
如下只能把网页分成3个小框,我要把最上面的那个框也分为左右两个框,请问怎样实现?

<frameset rows= "40,* " frameborder= "0 " marginwidth= "0 " marginheight= "0 " leftmargin= "0 " topmargin= "0 ">
<frame name= "top " src= "xx.html " scrolling= "NO ">
<frameset cols= "220,* " frameborder= "1 " >
<frame name= "detail " src= "sss.html ">
<frame name= "main " src= "kdk.html ">
</frameset>

</frameset>

[解决办法]
<frameset rows= "40,* " frameborder= "0 " marginwidth= "0 " marginheight= "0 " leftmargin= "0 " topmargin= "0 ">
<frameset cols= "220,* " frameborder= "1 " >
<frame name= "top1 " src= "xx.html ">
<frame name= "top2 " src= "xx.html ">
</frameset>
<frameset cols= "220,* " frameborder= "1 " >
<frame name= "detail " src= "sss.html ">
<frame name= "main " src= "kdk.html ">
</frameset>
</frameset>