条件组合 显示/隐藏多个单选按钮

我有一个简单的表格，当选择发布选项时，它会显示额外的选项。但是，我真正希望它做的是仅当从以前非常相似的单选按钮集中进行选择组合时才显示这些选项。所以总共有 3 组单选按钮。1. 英国或国外邮寄， 2.通过卡、账户或现金付款， 3.发布选项，您可以在下面看到。仅当客户选择英国作为目的地，并且付款是通过(卡或帐户(并且需要发布时，才应显示额外的隐藏发布选项。

<style type="text/css">
    .show { display: block;  }
    .hide { display: none; }
</style>
<script type="text/javascript">
    function showSelect() {
        var select = document.getElementById('my_select');
        select.className = 'show';
    }
</script>

<div id="post">
    <fieldset class="post" > 
        <legend>
            <span class="wrap3">&nbsp;Please choose method of delivery &nbsp;&nbsp;</span>
        </legend> 
        <ul class="radio"> 
            <li>
                <input type="radio" name="Postage_Method" id="post"  value="Post"  onclick="showSelect();"/>
                <label for="post">&nbsp;Please Post</label>
            </li> 
            <select id="my_select" class="hide">
                <option value="nxday">Next Day Monday to Friday </option>
                <option value="b9">Before 9 a.m. Monday to Friday </option>
                <option value="b10">Before 10 a.m. Monday to Friday </option>
                <option value="b12">Before 12 a.m. Monday to Friday </option>
                <option value="sat9">Saturday Before 9 a.m.  </option>
                <option value="sat10">Saturday Before 10 a.m. </option>
            </select>

            <li>
                <input type="radio" name="Postage_Method" id="post" value="Arrange Own Pick Up " />
                <label for="own">&nbsp;Will arrange own pick up</label>
            </li> 
            <li>
                <input type="radio" name="Postage_Method" id="post" value="Collect in person" />
                <label for="collect">&nbsp;Will collect in person</label>
            </li> 
        </ul> 
    </fieldset> 
</div>