表单提交

<script>
        /*这里是提交表单前的非空校验*/
        $(function() {
            $("form").submit(function() {
                var first = $("input[name='username']").val();
                var last = $("input[name='password']").val();

                if (first == "" || first == null || first == undefined) {
                    alert("用户名不能为空");
                    return false;/*阻止表单提交*/
                } else if (last == "" || last == null || last == undefined) {
                    alert("密码不能为空");
                    return false;/*阻止表单提交*/
                } else {
                    alert("提交");
                    return true;
                }
            })
        })
    </script>