select set the dropdown list according to user selection(radio button)
<p>I have two dropdownlists, namely A and B.</p>

<p>I need to set the dropdownlist A and B with two different values, according to selected radio button selected by the user.</p>

<p>There are two radio buttons namely R1 and R2:</p>

<ul>
<li>If user selects R1 then dropdownlist A should select <code>00:00</code> and B should select <code>08:00</code>.</li>
<li>If user selects R2 then dropdownlist A should select <code>00:00</code> and B should select <code>04:00</code>;</li>
</ul>

<p>Both dropdown lists, A and B contain  00:00, 00:01... up to 23:59.</p>

<p>How can I achieve this? Please any one help me.</p>
