我想在所有字段都有值之前禁用我的提交按钮。我该怎么做?
<html>
<head>
<title></title>
<style type="text/css">
</style>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
$('#register').attr("disabled", true);
});
</script>
</head>
<body>
<form>
Username<br />
<input type="text" id="user_input" name="username" /><br />
Password<br />
<input type="text" id="pass_input" name="password" /><br />
Confirm Password<br />
<input type="text" id="v_pass_input" name="v_password" /><br />
Email<br />
<input type="text" id="email" name="email" /><br />
<input type="submit" id="register" value="Register" />
</form>
<div id="test">
</div>
</body>
</html>