ajax/post请求

<script>
    window.addEventListener('load', function (ev) {
        var btn = document.getElementById('send');
        btn.addEventListener('click', function (ev1) {

            // 1. 获取用户输入的内容
            var account = document.getElementById('account').value;
            var pwd = document.getElementById('pwd').value;

            // 2. 创建网络请求对象
            var xhr = new XMLHttpRequest();
            xhr.open('post', 'http://localhost:3000/api/five', true);
            // 设置请求头
            xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');

            xhr.send('name=zs&age=19');
            xhr.addEventListener('readystatechange', function (ev2) {
                if(xhr.readyState === 4 ){
                   if(xhr.status === 200){
                       console.log(xhr.responseText);
                   }else {
                       console.log('请求失败！');
                   }
                }
            });
        });
    });
</script>