function check_submit()
{
var a = document.getElementsByName("check1");
for(var i=0; i<a.length; i++)
{
if(a[i].checked) return true;
}
return false;
}<form name="form1" method="post" action="" onsubmit="return check_submit()">
{
var a = document.getElementsByName("check1");
for(var i=0; i<a.length; i++)
{
if(a[i].checked) return true;
}
return false;
}<form name="form1" method="post" action="" onsubmit="return check_submit()">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>eee</title>
<script language="javascript">
function check_submit(){
var tag=false;
for(i=0;i<document.form1.check1.length;i++)
if(document.form1.check1[i].checked){tag=true;break;}
if(tag)
alert('OK!');
else
alert('请输入数据!');
return tag;
}
</script></head>
<body>
<form name="form1" method="post" action="">
<p>輸入;
<input type="checkbox" name="check1" value="1">
<input type="checkbox" name="check1" value="2">
<input type="checkbox" name="check1" value="3">
<input type="checkbox" name="check1" value="4">
<input type="submit" name="Submit" value="送出" onClick="return check_submit()">
</p></form>
<%=request("check1")%>
</body>
</html>