[danik.js]

Noscript вариант:

<style>
    button[name="action"] {
        border: none;
        padding: 0;
        background: none;
        text-decoration: underline;
        color: #284A67;
    }
</style>
...
<form action="/user" method="get">
    <input type="radio" name="id" value="666" />
    ...
    <input type="radio" name="id" value="777" />

    <button type="submit" name="action" value="edit">Редактировать</button>
    <button type="submit" name="action" value="delete">Удалить</button>
</form>

javascript вариант:

<input type="radio" name="id" value="666" />
...
<input type="radio" name="id" value="777" />

<a rel="action" href="/user?action=edit">Редактировать</a>
<a rel="action" href="/user?action=delete">Удалить</a>

<script>
    (function(){
        var actions = document.querySelectorAll('[rel="action"]');
        for (var i = 0; i < actions.length; i++)
        {
            actions[i].onclick = function(){
                var id = document.querySelector('[name="id"]:checked').value;
                location.href = this.href + '&id=' + id;
            }
        }
    })();
</script>