<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>jQuery</title>
<script src="
http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("input#aaa").change(function(){
var num = $("input#aaa").val();
if(num != '')
{
if(num%7==0)
alert("能被7整除");
else
alert("不能被7整除");
}
});
});
</script>
</head>
<body>
<input id="aaa" />
</body>
</html>