Не работает JS скрипт на странице

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
<script>
    $(document).ready(function(){
        $('#btn_submit').click(function(){
            var user_name = $('#user_name').val();
            var user_email = $('#user_email').val();
            var user_phone = $('#user_phone').val();
            var user_message = $('#user_message').val();
            var re_em = /^\S+@\S+\.\S+$/;
            var ru_num = /^[\d\+][\d\(\)\ -]{10,14}\d$/;

            if(user_name == ''){
                document.getElementById('user_name').style.borderColor = 'red';
            }else{
                document.getElementById('user_name').style.borderColor = 'green';
            }

            if(user_email == '' || !re_em.test(user_email)){
                document.getElementById('user_email').style.borderColor = 'red';
            }else{
                document.getElementById('user_email').style.borderColor = 'green';
            }

            if(user_phone == '' || !ru_num.test(user_phone)){
                document.getElementById('user_phone').style.borderColor = 'red';
            }else{
                document.getElementById('user_phone').style.borderColor = 'green';
            }

            if(user_message == ''){
                document.getElementById('user_message').style.borderColor = 'red';
            }else{
                document.getElementById('user_namemessage')
            }

            $.ajax({
                url: "action.php",
                type: "post",
                dataType: "json",
                data: {
                    "user_name": user_name,
                    "user_email": user_email,
                    "user_phone": user_phone,
                    "user_message": user_message
                }

                success: function(data){
                    $(.'messages').html(data.reset);
                }
            });
        });
    });
</script>
<title>Отправка письма</title>

[![введите сюда описание изображения][1]][1] [1]: https://i.stack.imgur.com/V5BBg.png