js判断frame？
<frameset name= "pdi " rows= "50,* " frameborder= "auto " border= "0 " framespacing= "0 ">
<frame name= "oper " scrolling= "no " src= "op.php ">
<frameset name= "main " cols= "105,* " frameborder= "auto " border= "0 " framespacing= "0 ">
<frame name= "unit " scrolling= "no " src= "unit.php ">
<frameset name= "right " rows= "50%,* " frameborder= "auto " border= "0 " framespacing= "0 ">
<frame name= "batch " scrolling= "auto " src= "batch.php ">
<frame name= "slab " scrolling= "auto " src= "slab.php ">
1.当前框架是oper这个框架，我想获得main下面有多少个frame？
2.unit,batch,slab框架的页面都有复选框，我想在oper的框架中做判断，只允许一个框架中有选中（比如unit、batch框架下的复选框都有选中的话，提示错误）。
谢谢大家！
[解决办法]
1. top.main.getElementsByTagName( "FRAME ").length;
2.判断
if(top.unit.document.formname.chkname.checked)..
if(top.batch.document.formname.chkname.checked)..
if(top.slab.document.formname.chkname.checked)..
如果chkname多于1个用chkname[i].checked判断
[解决办法]
每个frame的ID取上名字！ 用document.getElementById( "frameID ")就可以了
