<input type=checkbox onclick="o=document.all.div1.children;for(var i=0;i<o.length;i++)o[i].checked=this.checked">
<div id=div1><input type=checkbox><input type=checkbox><input type=checkbox></div>
<div id=div1><input type=checkbox><input type=checkbox><input type=checkbox></div>
<input type=checkbox name=c><input type=checkbox name=c><input type=checkbox name=c><br>
<input type=checkbox onclick="o=document.all['d'];for(var i=0;i<o.length;i++)o[i].checked=this.checked">
<input type=checkbox name=d><input type=checkbox name=d><input type=checkbox name=d>
{
for(i=0;i<document.form1.elements.length-1;i++)
document.form1.elements(i).checked=true;
}
function selectxiaoshuo()
{
if(document.form1.xiaoshuomanage.checked)
{for(i=4;i<=27;i++)
document.form1.elements(i).checked=true;}
else
{for(i=4;i<=27;i++)
document.form1.elements(i).checked=false;}
}function selectquyu()
{
if(document.form1.elements(28).checked)
{for(i=29;i<=42;i++)
document.form1.elements(i).checked=true;}
else
{for(i=29;i<=42;i++)
document.form1.elements(i).checked=false;}
}function selectkehu()
{
if(document.form1.elements(43).checked)
{for(i=44;i<=48;i++)
document.form1.elements(i).checked=true;}
else
{for(i=44;i<=48;i++)
document.form1.elements(i).checked=false;}
}
<input type=checkbox name=aa>
<input type=checkbox name=aa>
<input type=checkbox name=aa>
<input type=checkbox name=aa><br><input type=checkbox onclick="aa(this, 'bb')">all
<input type=checkbox name=bb>
<input type=checkbox name=bb>
<input type=checkbox name=bb>
<input type=checkbox name=bb><br><input type=checkbox onclick="aa(this, 'cc')">all
<input type=checkbox name=cc>
<input type=checkbox name=cc>
<input type=checkbox name=cc>
<input type=checkbox name=cc><script language="JavaScript"><!--
function aa(e, s)
{
var a = document.getElementsByName(s);
for (var i=0; i<a.length; i++)
a[i].checked = e.checked;
}
//--></script>
http://expert.csdn.net/Expert/topicview.asp?id=1447234