<FRAMESET COLS="25%, *">
<FRAME SRC="a.html" name="frame1">
<FRAME SRC="b.htm" name="frame2">
<FRAME SCROLLING="NO" SRC="graphic.htm">
</FRAMESET>//a.html
<script>
function f1()
{
window.parent.frames["frame2"].document.all.ck1.checked=document.all.ck1.checked;
}
</script>
<body>
<input type="checkbox" id="ck1" onclick=f1()>left
</body>////////////b.htm<input type="button"  value="oooo">
<input type="checkbox" id="ck1">right
</body>