[Decode]

<div id="myform">
    <input type="radio" class="radio" name="drink" value="1"   />Розница |
    <input type="radio" class="radio" name="drink" value="2"  />Опт1 |
    <input type="radio" class="radio" name="drink" value="3"  />Опт2
</div>
<input type="number"  data-action="13" value=""  id="contstrix" name="name" max="13" disabled="disabled"  />

<script>
    [].forEach.call(document.querySelectorAll('.radio'), function(item) {
        item.addEventListener('change', function() {
            var inpNum = document.getElementById('contstrix');
            inpNum.removeAttribute('disabled');
            inpNum.value = item.value;
        });
    });
</script>