全选<input type=checkbox value="Check All" onclick="mm(this)">
<script language=javascript>
function mm(o)
{
var a = document.getElementsByName("m");
for (var i=0; i<a.length; i++){
a[i].checked = o.checked;
}
}
</script>
<input type=checkbox name=chk>
<input type=checkbox name=chk>
<input type=checkbox name=chk>
<input type=checkbox name=chk>
<input type=checkbox name=chk>
<br>
全选：<input type=checkbox onclick=sel('chk')>
<script language="javascript">
function sel(a){
o=document.getElementsByName(a)
for(i=0;i<o.length;i++)
o[i].checked=event.srcElement.checked
}
</script>
