你看是不是要这样的效果??
<form name=form1>
A
<input name="a" type="checkbox" id="a" value="checkbox">
<span id=advance1 style="display:none">advance1</span>
<input name="a1" type="checkbox" id="a1" value="checkbox" onclick="cc('a')">
<input name="a2" type="checkbox" id="a2" value="checkbox" onclick="cc('a')">
<input name="a3" type="checkbox" id="a3" value="checkbox" onclick="cc('a')">
<p>B
<input name="b" type="checkbox" id="b" value="checkbox">
<span id=advance2 style="display:none">advance2</span>
<input name="b1" type="checkbox" id="b1" value="checkbox" onclick="cc('b')">
<input name="b2" type="checkbox" id="b2" value="checkbox" onclick="cc('b')">
<input name="b3" type="checkbox" id="b3" value="checkbox" onclick="cc('b')">
</p>
</form>
<script language="JavaScript">
<!--
function cc(sand)
{
if(sand == "a")
{
if(document.all.a1.checked != true && document.all.a2.checked != true && document.all.a3.checked != true)
{
advance1.style.display = "none";
}
else
{
advance1.style.display = "";
}
}
if(sand == "b")
{
if(document.all.b1.checked != true && document.all.b2.checked != true && document.all.b3.checked != true)
{
advance2.style.display = "none";
}
else
{
advance2.style.display = "";
}
}
}
//-->
</script>
<form name=form1>
A
<input name="a" type="checkbox" id="a" value="checkbox">
<span id=advance1 style="display:none">advance1</span>
<input name="a1" type="checkbox" id="a1" value="checkbox" onclick="cc('a')">
<input name="a2" type="checkbox" id="a2" value="checkbox" onclick="cc('a')">
<input name="a3" type="checkbox" id="a3" value="checkbox" onclick="cc('a')">
<p>B
<input name="b" type="checkbox" id="b" value="checkbox">
<span id=advance2 style="display:none">advance2</span>
<input name="b1" type="checkbox" id="b1" value="checkbox" onclick="cc('b')">
<input name="b2" type="checkbox" id="b2" value="checkbox" onclick="cc('b')">
<input name="b3" type="checkbox" id="b3" value="checkbox" onclick="cc('b')">
</p>
</form>
<script language="JavaScript">
<!--
function cc(sand)
{
if(sand == "a")
{
if(document.all.a1.checked != true && document.all.a2.checked != true && document.all.a3.checked != true)
{
advance1.style.display = "none";
}
else
{
advance1.style.display = "";
}
}
if(sand == "b")
{
if(document.all.b1.checked != true && document.all.b2.checked != true && document.all.b3.checked != true)
{
advance2.style.display = "none";
}
else
{
advance2.style.display = "";
}
}
}
//-->
</script>
多谢...