<label for="showtimes">Showtimes</label>

<select id="showtimes" name="showtimes"> 

    <optgroup label="1PM">

        <option value="titanic">Twister</option> 

        <option value="nd">Napoleon Dynamite</option> 

        <option value="wab">What About Bob?</option> 

    </optgroup> 

    <optgroup label="2PM">

        <option value="bkrw">Be Kind Rewind</option> 

        <option value="stf">Stranger Than Fiction</option> 

    </optgroup> 

</select>