7.1 验证邮箱
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
function check() {
var email = document.forms["myForm"]["code"].value;
var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
var res = filter.test(email);
alert(res);
return res;
}
</script>
</head>
<body>
<form name="myForm" action="demo_form.php" onsubmit="return check()" method="post">
<label><input type="text" id="code" name="code" ></label>
<input type="submit" value="提交">
</form>
</body>
</html>