老师，麻烦看下我的代码是否正确，需要优化吗

相关代码：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        form{
            width: 400px;
            height: 200px;
            margin: 0 auto;
            position: relative;
        }
        form span{
             margin: 0;
        }
        form button#sign{
            position: absolute;
            top: 40px;
            left: 60px;
            color: white;
            background-color: green;
        }
        form button#delete{
            position: absolute;
            top: 40px;
            left: 120px;
            color: white;
            background-color: red;
        }
    </style>
</head>
<body>
    <form action="">
        <span>用户名:</span>
        <input type="text" placeholder="请输入用户名" id="text">
        <button id="sign">登录</button>
        <button id="delete">删除</button>
    </form>
    <script type="module">
        import {set,get,remove} from './cookie.js';
        const text = document.getElementById('text');
        const sign = document.getElementById('sign');
        const dele = document.getElementById('delete');
        sign.addEventListener('click',()=>{
            if(text.value==undefined){
                return;
            }else{
                set('用户名',text.value,{
                    maxAge:7 * 24 *3600,
                })
            }
            window.location.reload();
        },false)
        dele.addEventListener('click',()=>{
            if(text.value==undefined){
                return;
            }else{
                remove('用户名');
            }
            window.location.reload();
        },false)
        !function(){
            if(get('用户名')==undefined){
                return;
            }else{
                text.value=get('用户名')
            }
        }();
    </script>
</body>
</html>