<SCRIPT LANGUAGE="JavaScript">
<!--
function checking()
{
var e = form1.id;
for( var i = 0; i < e.length; i++ )
if( e[i].checked == true ) {
alert("Yes");
break;
}
if( i == e.length )
alert("No"); }
//-->
</SCRIPT>
<form name=form1>
<input type=checkbox name=id>
<input type=checkbox name=id>
<input type=checkbox name=id>
<input type=button name=b1 onClick="checking()">
</form>
for(var i=0; i<a.length; i++)
{
if(a[i].checked) alert("有选中")
}
function fly()
{
var elem=document.all.tags("INPUT");
var j=0;
for (var i=0;i<elem.length;i++)
if (elem[i].type=="checkbox"&&elem[i].checked)
j=j+1;
alert("有"+j+"个选中!");
} </script>
</head>
<BODY>
<INPUT onclick ="fly();" id="Checkbox1" type="checkbox" name="ID">
<INPUT onclick =fly() id="Checkbox3" type="checkbox" name="ID">
<INPUT onclick =fly() id="Checkbox2" type="checkbox" name="ID">
<INPUT onclick =fly() id="Checkbox4" type="checkbox" name="ID">
</BODY>