白痴有关问题-js验证复选

<br />
<br />
$("input[name='Submit']").click(function(){<br />
  if($("input[name='activite[]']").attr("checked") == false){<br />
    alert('至少选择一个吧');<br />
   }<br />
   else{<br />
   location.herf = "reponse.php";<br />
    }<br />
});<br />

<script><br />
  function func(obj){<br />
       var boxs=obj.elements['activite[]'];<br />
	   var counter=0;<br />
	   for(var i=0;i<boxs.length;i++){<br />
	       if(boxs[i].checked) counter++<br />
	   }<br />
	   if(counter==0){ <br />
	     alert('必须选一个');   <br />
		 return false;<br />
	   }	<br />
	   return true;<br />
  }<br />
</script><br />
<form action = "reponse.php"  name="form1" method = "post" onsubmit="return func(this)">